There is a simple, although probably incomplete, explanation: men gain more from being successful. In particular, that's basically the only way for men to get

There is a simple, although probably incomplete, explanation: men gain more from being successful. In particular, that's basically the only way for men to get rich (while for many women marrying a rich men is also an option), and women view more successful men as more desirable, where men don't care as much about women's successes. It would be interesting to explore if there are any differences in the gay populations.