It's not an excuse to exclude, and you're right that a homosexual relationship shouldn't be more "adult". But there are a lot of problems in the way the relationships have been presented that will turn people off to changing their minds anyway. I really don't want to see anyone kiss on TV unless it's for a good reason, if it's two men doing that it's going to naturally turn more people off because of the conditioning they have to associate what they see now with porn or what have you. Right thing? No. But that's how it is and you should work around that. You won't change people's minds by turning them off by just throwing these things in to make them like it. I know people can do the same thing with a heterosexual relationship and no one thinks of it like this but one is stigmatised, and the other isn't, and so the degree of exposure brings about different feelings on the intent.
I mean this isn't the only time I've disagreed with people who I otherwise share a goal with. I support freeing the nipple but not #FreeTheNipple because going to town squares, ripping off your top, and demanding national coverage will just attract perverts, creeps, and make it a spectacle, just making the entire case worse for everyone.