So why do all the posters that show a number of yoga asanas, always depict men???

I wonder if it isn't just that men are in general less flexible than women, and because they tend to see everything as a competition, don't like being in a class where the women "do better" than they do (even though that's not what it's about - and yes I know that some women can be competitive in yoga class, it's definitely an impulse that I struggle with ).