Vanhattan: The California Supreme Court addressed your argument directly. Calling this argument "Sophistic" because such a choice negates the persons sexual orientation.
This seems to me like arguing that equal protection requires the definition of "arms" in the Second Amendment to be understood as including protest signs, because otherwise pacifists would have little use for the "right to keep and bear arms." Equal protection doesn't mean that all rights have to interest all groups equally. The fact that some people have no interest in the relationship described by the traditional definition of marriage doesn't mean that that definition is unconstitutional.
Yes. It would be interesting, wouldn't it, if pacifists and anti-gun folks took to the streets shouting, "But what does the 2nd Amendment do for me? It lets people who like guns have guns, but what do I get? They get something, but I don't! My equal protection rights have been violated. It's not fair!!!"