Actually the fights are quite different. Two men kissing is just really icky. In public, it's disgusting. A bare-shouldered woman is not. Maybe provocative depending on the shoulders. But definately not icky or disgusting. That difference is never going to change. The vast majority of people will always, either publically or in secret, regard two men kissing as stomach turning.
That's why homosexual marriage will only be imposed by courts or aberant leftist legislatures (maybe).
It can be a whole lot worse than two men kissing. If you happen to live in a city like Seattle or San Francisco there are a lot of gay men who seem to seriously consider having sex in a public restroom as a civil right. Once in a blue moon the police will decide to bust them, (remember George Michael), and then they'll start screaming about homophobia, discrimination, racism and everything else. Everything that is but acknowledging that there is something fundamentally wrong with "screwing" in a public restroom.