KH fans have the unfortunate problem of being fans of a series that gets prequels, sidestories and sorta-sequels released frequently. This makes any fanbase dangerously obsessive with its plot and goes crazy easily.
Also they get way too attached to characters. Like at any given point you can just go ahead and find someone writing essays on why character X doesn't suck and people are just being unfair to his/her darling character. It's weird.
Not all KH fans are bad, it's just that...there are some that are really, really creepy.