Take women out of the equation and you're left with sex obsessed men.
I think you’ve got a point there. Most of the gay guys I know are rather promiscuous, in the “So I met this cute guy at a bar and we went back to his place...” way, but most of the lesbians I know are in relationships and wouldn’t think of having sex with a random person they picked up at a bar. When you look at STD transmission rates, they’re astronomical among gay men, and on the lower side of average for lesbians. Maybe it is the tendency of men to want sex and women to want a relationship that’s just exaggerated when they’re in a relationship with someone of their own sex - granted, there are exceptions, but that’s how it seems for the most part.