I'm in a unique position. I identify with femininity much more than I identify with masculinity. But one thing I don't have in common with most women, and have in common rather with most men, is the fact that I am attracted to girls, and not guys. Which keeps me from feeling entirely female in the standard sense.
I imagine women must have some kind of biological impulse to consider other attractive women as competition for the men in their lives. I, on the other hand, am preoccupied with considering attractive women as potential sex partners (which, incidentally, puts me in a great position to encourage women who express themselves sexually, rather than jealously shame them as sluts).
Thus, though I might feel more comfortable hanging out with girls, doing girly things, there is also a sexual component that undermines the motive of gender segregation (that is, the idea behind the traditional practice of not allowing boys and girls past a certain age to live under the same roof unless married). This puts me in a difficult place, the same place in which I imagine most homosexual individuals must feel every time they have to change in the locker room (not that it's necessarily a bad one to be in ^_-).
But if the idea is to separate persons who may have a sexual attraction to one another, does it even make sense to segregate by gender? You might get the majority that way, but now you're making a different set of rules for homosexual people than you are for heterosexual people, and that's not fair.
Do we really need to separate boys and girls that strongly for fear that spontaneous orgies might break out if they had to change or bathe or sleep in the same room? I doubt that would happen very often even with teenagers, who are notorious for their supposed 'raging hormones' (and those that want it are going to find ways around the rules anyway). Or are we so tied to the idea that, presented an opportunity, men will sexually abuse and exploit women who are too weak to protect themselves? Sexist much?
I think an ideal world is one where the sexes can intermingle peacefully, and where men and women both have the responsibility not to misbehave toward one another regardless of whether or not they have to share some of the same spaces, and engage in some of the basic activities of life together (living, sleeping, dressing, bathing - god, can you imagine if we didn't even allow unattached men and women to eat together?). And on the topic of bathrooms, I like privacy when I use one, but that's because I don't want other people around - it doesn't make a damn difference to me whether the person in the other stall is male or female!
Maybe I'm biased as a nudist, but even though I delight in seeing attractive girls' naked bodies, I know how to behave myself in the presence of one. Furthermore, I believe that being periodically exposed to that sight enhances the quality of my life
(which is why I embrace rather than shun those opportunities), and I think we all would be a bit less neurotic about sex and nudity if we were exposed to other people's bodies with a bit more regularity. Especially during puberty...