I think a protagonist who can't relate to is a good reason to not play a game.
But of course it's not just about that: I generally don't like where the story is going.
I'm not in this FFXIII Versus stuff, at all.
I know the story got worse with time - or I simply grow up, or maybe both -, and that's why I have to turn off my brain a little bit when I play (so I don't think too much about the unnecessarily convoluted plot, the awkward dialogues, the plot holes ecc.) and I can enoy what KH can still give to me: a tons of fun in Disney's worlds and good interactions beetween characters I love and I grow up with.
But without that, what remains to play for?