Anecdote: as a bisexual guy (now married to a woman), dating women was much, much harder than dating men. This extends beyond sexual encounters to actual relationships: for every relationship opportunity with a woman, I'd guesstimate I had five opportunities with men. And I essentially never had the opportunity to date a woman with over half my income (at least until I met my wife), while I regularly dated men making substantially more than me.

I think the mismatch is largely due to implicit standards on the part of women (must be a certain race, must be at least average height, must be gender conventional) that are so ubiquitous that they don't even consider them standards.