Seems to be fandom's usual approach to characters. Female ones, at least. (Males are to be universally loved and praised.) I look at it about the same as I do the mindset where most females are hated/tolerated/disliked/dismissed/don't-have-time-for, but praise is expected for liking one or two.

I suspect it's Hikaru's character type. I think Miaka (the extreme of the character type) kind of makes people automatically be harder on the character type.