I’m actually kind of surprised we haven’t already seen a Mega Pikachu.  I’m not in the habit of making predictions, but there’s a tentative one for you; Pikachu will eventually Mega Evolve.  Having said that, this is sort of a tricky question – not for gameplay reasons because, like, sure, whatever (most unevolved Pokémon would need much larger stat increases than normal in order to be worth using over another Mega Pokémon, but there’s no reason we can’t give that to them); more so for whether and how it fits into the world.  At the Tower of Mastery in Shalour City, the Guru calls Mega Evolution “a transformation of Pokémon that were thought to be unable to evolve any further,” and while it’s pretty clear that the characters in X and Y do not by any means know all the rules of Mega Evolution, not even him, I think it’s telling that the writers would choose to emphasise the fact that only fully-evolved Pokémon do it – he actually mentions this before bringing up the fact that it’s temporary, which seems like it should be a more important point.  I think there may be an idea in play that, because Mega Evolution “transcends” normal evolution, because it’s above and beyond normal evolution, it would not make sense for Pokémon to be able to do it before completing their normal evolution.  Unless the evolved Pokémon can also Mega Evolve (in which case why are you even using the younger one?) then evolution for that species would become a loss, a sacrifice; it would mean being cut off from this “transcendant” state.  I don’t think Game Freak would like that notion.

1) Well, the obvious answer is for gameplay reasons, but that’s probably not what you’re asking.  I think a good starting point would be thinking about what ‘knowing’ a move actually entails.  Do they just get these powers, have them, and then never have to practice them?  I’d think not.  I mean, that’s not how martial arts or sports work in the real world.  You have to practice your skills constantly in order to be any good, and it’s not like you can just, like, practice firing a Flamethrower straight forward on level ground and be done with it; you want to be accurate from as many different positions and under as many different conditions as possible.  Maybe five moves is just too much for most Pokémon to keep up that kind of skill level?

2) I think Ludicolo is actually sort of a bad example, because Pokémon that evolve using stones normally lose the ability to learn most moves by leveling, and that’s probably to do with the same ‘old dog, new tricks’ mentality that’s behind most evolved Pokémon learning the same moves but more slowly – the older forms are more set in their ways; they might learn new applications for skills they already have, but completely new abilities are just more complicated than they want to deal with.  A more interesting example would be the transition from Lotad to Lombre, because Lombre actually continues to learn new moves, just different ones – Fake Out instead of Mist, Water Sport instead of Mega Drain, and so on.  Obviously nothing physically prevents Lombre from being able to use the moves Lotad could learn, but it won’t learn them if you try to teach it, and I think maybe that’s because, specifically for Pokémon that work like this, learning the move is somehow tied to the mindset that comes with being smaller and weaker.  Once they’ve got the skill they can maintain it by remembering how they felt when they learned it, but if they never learned it in the first place they just can’t see themselves needing it in the same way – like “sure, little kids have to learn to do that to protect themselves (or something) but I’m grown up now; why would I need that?”

Question continues: “…would like to NOT face those. Some will maybe want to face certain Gym Leaders or Elite Four, while others would be afraid of them? I feel like this has the potential of being very annoying, but also it can be developed into a whole new game mechanic of managing Pokemon desires / convincing them of something. (For example, train a Pokemon against many Bug-types to make it less reluctant to face a Bug-type Gym Leader) What do you think?”

I very much think that this would be a good thing to have.  I actually made a similar suggestion here and some other bits and pieces here, but in both cases it was sort of tangential to wider points I was making and I didn’t really talk about it from this angle.  I sort of suspect that the reason Game Freak don’t try something like this is because of the sheer number of Pokémon that people often collect in the course of playing these games, and how utterly unmanageable it quickly becomes to try giving even a thin semblance of personality to each of them (that, and I can imagine it being very difficult to write this kind of content, given that Pokémon don’t talk).  However, I think a kind of modular quest system along the lines you describe would have the potential to work quite smoothly – some quests that can be offered repeatedly by many Pokémon, others that can only happen once, some that are offered by Pokémon of a particular type, or species, or nature, maybe some that are triggered by things like using unusual items in battle or being knocked out under certain circumstances… and it doesn’t have to be all of your Pokémon doing this all the time in order to create at least a general impression that some of them, some of the time, might speak up with particular desires.  Something similar worked for the Digimon World games, after all.

Here’s the video, for the benefit of other readers.  It does a good job of explaining some tricky concepts; it’s worth watching.

So… the thing with Pokémon.  The thing with Pokémon is that Game Freak’s idea of balancing it – as far as I can tell – is just to shake things up regularly, to the point that a stable metagame never forms in the first place.  New Pokémon, new TMs, new move tutors or new forms of existing Pokémon turn up practically every year, while older Pokémon don’t actually get banned or anything but may become more difficult to get hold of as the games to which they are native get older; meanwhile there are several different formats like doubles, so that a Pokémon which is useless in one is actually quite good in another, and then official tournaments will often do things like restrict players to one generation, which mixes things up a great deal.  When they do formally ban things, there’s almost no rhyme or reason to it; they ban a Pokémon based on its status as a ‘high-tier’ legendary, not based on how good it is (probably because they don’t actually know) – stuff like Mega Kangaskhan would never be banned despite being ridiculous; stuff like Zygarde would never be allowed despite being mediocre.  The end result is that there are a whole lot of different contexts in which one can play Pokémon, and it’s almost certain that none of them are actually ‘balanced’ in themselves, but there are so damn many of them that it doesn’t actually matter, and none of those contexts lasts more than a year or so before the next random shake-up anyway.  Meanwhile you have a sort of power creep happening because Game Freak only ever give new stuff to Pokémon – they almost never take it away, which means that a Pokémon who, through no fault of its own, doesn’t get something shiny and amazing in every generation steadily falls behind as other stuff gets stronger.  The situation of ‘perfect imbalance’ described in the video is a lot more like what Smogon tries to achieve with their tier system, where a Pokémon can rise or fall within the system as people discover ways of using it or countering it. However, because Smogon doesn’t actually control the game and can’t issue patches or make balance tweaks, they can’t build the kind of carefully calibrated imbalances that the video talks about – the can only pick things to ban or unban from different levels, which is haphazard at best.  Moreover, because so many people just don’t fully understand what the hell they’re trying to do, it earns them as much scorn as praise.

And then Game Freak tops it all off with whipped cream and a cherry by tossing in Mega Rayquaza, a Pokémon so ridiculously overpowered that even the other ridiculously overpowered Pokémon can’t deal with the damn thing.

To be honest, I gave up caring at that point; I think Mega Rayquaza was the straw that broke the Numel’s back.  Pokémon as Game Freak and Nintendo run it is just not a serious competitive game and never will be, and that sort of doesn’t matter because it’s not trying to be, not really.  Perhaps as many as two thirds of the Pokémon in the game are just objectively worse than other Pokémon that do basically the same thing, and a lot of the skill involved in the game is in team construction, so ultimately the big hurdle is in figuring out which Pokémon are ‘good’ and which ones are ‘bad,’ but that whole process is counterintuitive to a lot of players because the game encourages attachment to individual Pokémon.  Ultimately, I’m starting to think it’s better just to go with it – do stupid stuff, like play a single-type team, or take your playthrough team to a tournament, or actually use Corsola.  Do Nuzlockes.  Play with other people who like doing stupid stuff.  If you want a game that’s actually balanced, there’s always online simulators and Smogon rules.

We-ell, I don’t know if it’s entirely fair to generation II to draw such a sharp distinction – generation I has its share of pretty useless Pokémon that are hidden away in frustrating places.  I mean, you mention that Azumarill and Yanma were much weaker originally than they are now, but the same is true of Scyther and Pinsir, who are some of the Safari Zone’s rarest Pokémon; Pinsir is rubbish in generation I (indeed, Pinsir is sub-par in everything up to and including generation V), and Scyther’s not great either.  And need I even bring up Porygon?  Meanwhile, one of the swarming Pokémon available in generation II is Tauros, who was amazing in generation I.  I think the main problem is that what makes a Pokémon ‘good’ is often kinda difficult to anticipate without actually using the damn thing for quite a while, and particularly in the beginning Game Freak a) didn’t have a whole lot of experience with that and b) didn’t really care all that much either.

I did notice, while prepping my Tentacool for contests.  I think it’s nice to have another way of raising affection – those minigames are fun and give a nice sense of just spending a little quality time with your Pokémon, no battles or other nonsense, but they do start to drag on a bit after a while.  I also think it maybe says some interesting things about battles versus contests and friendship versus affection, because fighting and winning is the most straightforward way of raising friendship.  Battle mastery tends to be portrayed as involving a gradually strengthening bond of trust and camaraderie, culminating ultimately in the kind of spiritual unity that makes Mega Evolution possible, among other things.  It’s some heavy stuff, potentially some philosophically demanding stuff, and certainly not for everyone.  Contests and everything they involve are more about just being happy, encouraging creativity, and enjoying your time together – obviously they’re still a lot of work if you want to do it right, but no one has to get beaten up or watch their friends get beaten up.  Lisia’s very lighthearted worldview makes a lot of sense in this context.