There is a lot of conjecture on both sides of this issue, and I'll freely acknowledge I may be completely wrong in my assumptions here. But is it really so hard to believe that maybe the actual demand for female glamours is just higher than that of male glamours? I mean, women's clothing departments are much larger than men's in the real world, even though men actually spend more on clothes. See also: the Style Savvy games, Barbie dolls, etc. These things are marketed almost exclusively to women, and focus largely on women's fashion over men's.

Also, again, the fact that the game used to be very gender balanced and has skewed towards women implies that that is what the market actually favors. Clearly Square Enix didn't have a glamour bias at the start of 2.0, where do you suppose it came from?