Men are celebrated for their sexual conquest while women are denigrated for their conquests...
Its not a conquest if you don't have to work for it.
There was actually a GQ article I just read today about this new service for women that gives them "stand-in dates," attractive men that they take to family gatherings, celebrations, parties, etc. Its strictly for dates no romance, or sex is allowed.
The creator of the creator of the service "Rent-a-Gent," Sara Shikhman said,"Women can get sex anytime for free,"
And she's right. For the vast majority of women, there is a pretty constant stream of potential suitors and mates, he women don't even need to be attractive or put themselves out there.
I hate using male-centered logic, but it is harder for guys to have sex, a hell of a lot harder. Even attractive guys have to put in effort to pursue sex. When a woman can have her pick of men, and she chooses them all, of course she'll be denigrated. Because its both unnecessary, and say something about how she views herself.