Like I said, my reasons are really kinda petty. I just don’t like the change from happy, smiling Koffing to bloated, miserable, lung-cancer-y Weezing. It actually is quite a creative design, and you could even interpret it as illustrating the accumulating detrimental effects of air pollution (or cigarettes?) on a person’s health, and I can easily understand why other people would like it. It’s just not my cup of tea, personally.