Because they want to, same as the men that do. Anything wrong with that?
Nothing wrong with a woman spreading her legs ! Some of you guys obviously don't seem to have heard of sexual equality ? As is stated above, men do it, so women will do the same.
The only main reason most men have open legs is because of Testicles !! Get those caught between your thighs and you will soon understand why guys spread their legs.
Who decided on this site that all women should be or act demure with their legs crossed or closed ? It's a personal choice like anything else is.
I can't say it's true for all of them, but for many of the ones where you see profile pictures that look very sexually explicit in nature, it is highly possible because those photos were downloaded from a porn site in order to have nude photos on their profile. I have received many friend requests from profiles that are probably not from the person they claim to be, but I was foolish and accepted some of them anyway.
Aren't there two issues here? What do they mean by the pose and what does the viewer see? Maybe don't judge the pose before you've judged your viewing intention, if indeed judging is appropriate.
That's the point at issue. The site rules regarding uploading pictures says, "No Spread Eagle/shots where the butt, genitals or anus are the main focus point." So it's a matter of degree, or a matter of opinion if you like. If the man-spreading or woman-spreading is done such a way that the poser is calling attention to the genitalia, it's no good for the site.