I actually really enjoyed Kimahri as a character, but I think that as far as the storyline goes, he can be easily out shined by almost every other character for the obvious fact that he doesn't talk for a good portion of the game, that makes it easy to focus more on the other characters that have regular dialogue and interesting stories to tell. The same kind of thing can be said for the battles he tends to be out shined by the heavier hitters such as Auron, Tidus, and at times Wakka, simply because his attacks are not generic, also, with Kimahri on the sphere grid, he can go many ways and sometimes that makes him hard to upgrade in a specific class. that is just my opinion on why he is hated on, but I personally love him, he just takes a little longer to understand then the others