Because we live in the age of enlightenment, or some such crap. A minority is getting to tell the vast majority that they must give preferential treatment.

Anything that makes someone not operate within the biological method of reproduction is removing them from the gene pool unless they decide to use in vitro fertilization or something that's done medically.

BTW- before you know who tells me I'm a homophobe, there's no malice in my comments.