To be honest shante, I still reckon the reason for it was answered very early on.

The female meshes are more popular because it's easy pickings for blokes to view tits and ass in any pose we wish.  It might sound crude just coming out with it like that, but you know what I mean, there's no other way to put it.

I reckon it's the power of tits and ass, nothing more, nothing less.

Fair enough, for some there's the attraction of experimenting and using it for other things like space scenes, butterflies, and fluffy kittens or whatever, but I reckon even those that use it for universally rated stuff like that will still have produced some form or CG porn or erotica with it (most of them, anyway).  I suppose some of the elderly might not use it like that.  But for the most part the temptation is too great not to, especially when you look at the majority of the stuff that is being made for the figures.  We only see that stuff because it's popular, and vendors make it because it sells.

It sells because that's what the majority of people want it for.