I have to say, it wasn't the repetitive formula that drove me away- I can deal with a lot of "the same, but with x", as long as the "same" is good enough- it was the awful designs for the newer Pokemon. All of the first generation looked a lot like actual animals. Or, at least, actual enough animals. Except for the psychic types- which worked. Generation II wasn't too bad, except for the legendary ones most stuff still looked fairly reasonable. After that...they all looked like an intro to graphic design class threw up on them.
I don't know if they were trying to establish more of an overall "look" for Pokemon, but they're just...awful. Even the most "normal" ones still look like animals with bits stuck on them.
