Boy, are you out of it :-)
The women that hang around gay bars and clubs don't have sex with the men.
They just enjoy the environment, and have a lot of gay male friends.
A few will get infatuated with gay men and fall in love with them, but they're doomed to be disappointed.
"Fag Hags" as they're called, include a heck of a lot of really intelligent, hot women. They still will attempt to meet straight men, etc, but they hang out at gay clubs as a way to escape from the meat market of regular bars.