hahaha. i'll give you that one. nothing beats "your face".
anyway, the difference between the enthusiasm between the men and women can be explained as follows:
one - women's pictures will be inherently sexual... once one girl posts some t&a, it takes the thing to a whole other level. the men's pictures are largely just faces. women aren't judging anyone by their penis size but some of the girls are flashing a little cleave or ass or whatever. it's sexual versus judging-guy's-faces. not quite equitable.
second - the women will get a lot more scrutiny than the men. this is purely for demographic reasons... there are few women (or gays) to discuss many men, and many men to discuss few women.
third - i don't want to say self-respect, because it's not exactly a self-respect issue but i don't know how better to say it. i don't need a bunch of people on an internet forum judging me against other girls because i like me regardless of whether or not they do. and it's not insecurity, it's just self-assuredness and a complete lack of INTEREST in what any of you have to say about my looks.
fourth - and this is really just an afterthought, but i think that the girl who posts the most provocative picture will win anyway, and i wouldn't ever take a provocative picture of myself for public consumption.