Well, brokebackbabe, actually I'm not sure I agree with your premise.
I guess to the extent that straight people accept lesbians more than they do gay men, it's because according to cultural stereotype lesbians are more "masculine" than straight women and gay men more "feminine," and masculinity is more valued than femininity in this society (and pretty much every other one).
Oh yes. The male is the "better", worth striving for standard. Women in male domains get usually praise and admiration (e.g. women in car racing or "typical" male professions). Men in "typical" female professions or domains? What do you think a men gets to hear when he loves knitting as a hobby? Or a man who stays at home with the children (and his wife has a paid job)?
So, for example, nobody minds much if a girl is "tomboyish," if she prefers boyish clothes or playing in groups of boys -- often, she's even seen as being cooler or smarter or more skilled than girlish girls. But it's much less acceptable for a boy to be a "sissy," wear effeminate clothes, play with all girls -- that is seen as demeaning and shameful. The same prejudice extends into adulthood. I'm not saying those things are necessarily linked to sexual orientation, but in society's collective mind they are, and therefor the double standard of prejudice.
Again: oh yes! I have two living examples here in my home: one of my girls is a tomboy. From early age on, she never wanted to wear a dress or skirt, had her hair trimmed down to a a few millimeters, she wanted to have a crane for her birthday, always played with the boys, wore clothes in darker shades, hated pink and shirts with flowers, etc, etc.
And everybody found her
cool. The boys liked her because she was "one of them", the girls admired her coolness, the adults said she has guts and assertiveness (which she has). In short: she got only positive reactions.
Now my boy: he's almost four and loves everything pink. He loves to dance (ballett-wise, at least he tries, that's so cute, lol), wants desperately to be a princess or a fairy, wears the dresses of his older sister (not the tomboy, I have another girl) and nail polish, wanted to have a fairy costume for Christmas (and got it), plays mostly with girls, and so on.
Do people think he's cool? No. And what does he get? Admiration? Praise? Rarely. Well, at least he doesn't get any rebuff either. But there have occasionally been people who ask
me if I'm not worried about him. No. I'm not. Why should I? But never had anybody asked me if I'm worried about my tomboy girl.
Look at the job world. Which jobs are better paid? Typical female jobs, like medical secretary - or tapical male jobs like a car mechanic? Look at successful female managers, or our German Bundeskanzlerin: her fav clothing is a suit for females (trouser-suit?; not sure about the translation). Ever seen any male top-manager in a dress?
The male is the standard. A woman behaving manly "upgrades" herself, a man behaving womanly "downgrades" hisself.
Another reason for wider acceptance of lesbians than gay men is a historic one: for hundreds, almost thousands of years, it was common sense that women don't have any sexuality at all. So when they're not sexual beings, they can't be homosexual.
