Why are people only against male gays?

I've noticed that lesbians, ie female gays, are much less stigmatised. When people denounce homosexuality, they are usually referring exclusively to male gays.

People don't seem to be as morally outraged by lesbians, they are seen as more or less inconsequential, or mildly amusing at worse. Quite a lot of straight men (some "straight women as well) would even openly admit to finding lesbianism attractive in some cases.