I think part of is that Hermione was my gateway-drug to the HP-verse, and a lot of stuff, people seem to like doing that "only one smart/clever/ok/not obnoxious" girl thing with her, so all other girls sort of fail by comparison (which is highly annoying). Possibly with some over-identification with the "smart girl who was mocked by the not-as-smart-girls" going on.

Anyway, I'm going to have to track down more fic with her in it now.