How come some plants are pokémon, but most are not? Humans are the only known non-pokémon animal in existence (besides pokédex mentions of Indian elephants and stuff), so is there some kind of bias because the world’s environment and obstacles isn’t made out of meat?
I think probably because if all plants are Pokémon too then you begin to run dangerously short of things that are okay to eat. Game Freak seems to be very uncomfortable with the idea that humans eat Pokémon, at least in the present day – hell, in recent years they even seem to have become uncomfortable with the idea that wild Pokémon eat each other. When you ask them about it, they make reference to the huge variety of wondrous fruits and vegetables that exist in the Pokémon world. I suspect if all the plants become sentient too then they run out of wriggle room.