IMO Ginny's too cardboard to hate. Disappointment, I guess, is my strongest reaction.

I used to feel exactly that way about Ginny, too. Until I read HBP. But HBP was just too much for me. Too many instances of JKR trying to make Ginny sympathetic by doing unsympathetic things. Before that, I had felt that Ginny was a badly-written character, and that JKR had failed miserably, if she wanted me to care about her, or find her interesting, but I didn't see anything worth hating.