More socially acceptable is part of the problem-- a man who says he didn't want advances from/sex with a woman who's at least reasonable attractive will mostly be told he doesn't appreciate his good luck.

I don't know quite how relevant and which way the causal arrows are pointing, but this seems to add up somehow with the fact that on average women get more dates and more mates than men, explained by the phenomenon that fewer men date and mate way more women. It also seems to clash up weird with the social notion that women should be more selective of their partners while men should go for whatever's hottest or, failing that, available. (terminology intentionally representative of what I perceive to be social norm)