There has always been the danger that the more assimilated we are, the more we will become like them and therefore lose what makes us unique. Assimilate us, and eventually we disappear. This has been a danger for Jews, for black people, for women, for Native Americans, and for every wave of new immigrants to arrive on these shores. It may be that assimilation means loss of identity. Assimilation has been the technique our culture has used since the beginning to cope with new populations: It will make them like us.
This is bad because the gay community has learned how to conduct its romantic and sexual relationships without benefit of the law. That’s major, and in that area we have it all over heterosexual people. We conduct our relationships without benefit of divorce, charges of adultery, property settlements. We know the difference between sex and love and can talk about which persons are available as sexual partners without having the state play a part in any of these arrangements. And when necessary, we know the point at which our agreements among ourselves need to be re-negotiated. If we’re assimilated—just because there are more of them than there are of us—the probability is that we will drop all this and take up the practices of heterosexuals. 
We have developed a way of preserving the freedom of individual persons while enabling that person to form various kinds of important  relationships. We know how to conduct long-term relationships without any officer of the state anywhere to be seen. Every week, as new states offer marriage equality, we see pictures of couples who have been together twenty, thirty, forty years, who are now getting married. We have been refining our ability to live long and successful lives with no partner, and we show every week that we know how to live alone. We already know how to do it. We make a contribution to our culture just to the extent that we don’t allow heterosexuals to make us forget that we know these things. We need to teach them what we know. We need to say, very loudly and repeatedly, We know these things. And then we need to say, You folks need to learn what we know. 
There’s another reason that it’s bad for us to assimilate. If we care about the civilization we are a part of, we care about preserving our ethnic heritage—that is, the ethnic heritage of gay people— just as much as we care about the ethnic heritage of the various waves of Africans who were brought here or of European Jews before and after World War II, or of the tribes of Native Americans who’ve always been here.
What we need from heterosexuals is the equal protection of the laws. What they need from us is our difference.