Isn't it more likely that the USA women's team would win the world cup than the men's team? In which case, they won't want to risk sharing that money LoL (although I remember the men's team doing super well in the 90s and I supported them all the way when England dropped out).
The women cynically wanted more. The men can also deal with more risk because they get paid more playing for their clubs.
Ooops! Be careful what you wish for ladies!