I still reckon that either "bisexual" should be taken less literally or "pansexual" should be considered a more accurate replacement for it.
I have a theory on this. "Masculinity" and its associated concepts tend to be considered more positive/worthy/valuable/desirable/etc than "femininity". So women acting like men may be lifting themselves up beyond their sex, while men acting like women are degrading themselves.
Another theory of mine that either complements or contradicts this one (not sure which) is about the "third genders" some peoples have. These, to the best of my knowledge, are nearly always men acting like women. My theory here is that, for similar reasons to the first one but more focussed on official hierarchy, it is okay for a man to choose to lower his social position, but it is not okay for a woman to attempt to advance beyond her proper place.
I know these are very flawed, and I'm curious to know what anyone else thinks of 'em.
Only if you have "if you're not with us you're against us" on your mind, but I guess I see what you mean. But I like what they're doing at my uni, so *shrug*.