Why can't government just piss off and let people live in any group based on any membership they want free from harassment for it? Why should other people have government backed power over them? For what purpose?
If someone wants to believe that homosexuality is wrong, then why does anyone gay want to join in the first place? What's the point? It's just idiotic laws backed by aggressive activist groups who simply want to annoy others.
Any group should be allowed to hold whatever views they want, and control the membership they want. Even if those rules are morally wrong, as long as they are not committing criminal acts against anyone, they are not being harmed.
Not being admitted into a club is not damaging to anyone. If anything, being in a club that doesn't want you as a member seems like a worse situation to be in. The only clubs the government should be concerning itself with is are the ones it runs itself.