What good is there in homosexual marriage?

Is that a fair question?  Let's put it this way:  what good does it do for society?  Or is that a concern to anyone?  Is the individual's desires more important than the society in which he lives?  Are we to expect that everybody is to live with only their own interests and desires as their guide posts?  Is there anything else that we should be concerned about besides just ourselves?

If everyone thought that way, that is, in a purely selfish way, would a civilized society even be possible?

For a society needs replenishment of its numbers.  Homosexuals cannot reproduce.