Neither can heterosexuals so I'm not sure what your point is.
Here's my point. Let's take a "Jamestown Colony" situation, i.e. people having to survive in a state of nature, or harsh conditions.
Heterosexuals can do it because they can have children to (eventually) share the workload and care for the previous generation. The heterosexual "means" of sex is what the human body is designed for, thus there aren't the horrendous diseases and health problems that homosexuals have etc. Heterosexuals are also far more emotionally mature to deal with such a situation, and would construct social and moral structures (nuclear marriage, standards of moral behavior, helping out neighbors, etc.) that would engender survival. Homosexuals, being naturally self-destructive, immature and selfish, could not bring themselves these things.
In short, if you took a group of 200 heterosexuals and put them in a state of nature, and then came back a year later to see how they were faring, some would have died but most likely could hang on. Take a group of 200 homosexuals in the same situation and you'd come back a year later to find 200 skeletons and a bunch of fat buzzards. Homosexuals are far too immature, selfish, and self-destructive to survive in a situation like that.
They can only survive in the context of a heterosexual society. Thus, we can live without them, and they can't live without us. Thus we can regulate their behavior, and because their behavior is uniformly negative and destructive to society (higher health costs, child molestation, etc.) we should.