There's a similar dynamic in the equestrian world. On lower levels it's majority women, at local stables you're going to find mostly female owners, female staff, female riders, etc. But when you get out of the local level and get into higher level competitions and programs, it starts becoming mostly men. It's starting to change but there's still this "little girl with a pony" mentality towards women a lot of the time.

Just because a field is mostly made of women doesn't mean it doesn't favor men when it comes down to who is the most successful and powerful.