That is *exactly* what would happen.

I believe you. In fact, it could be a new Game/Meme: name a fandom where a woman is almost universally loathed and swap the roles of loved male/hated female. Would the fandom still instinctively prefer the male character to the female, using particular "characteristics" for justification?

Trying to think of a suitable fandom now, if I do I'll let you know!