It might not be the best comparison but it might be somewhat illustrative. There is the NBA. But along come the women who say, "Hey look at us, we can play basket ball too!" The majority of BB fans shrug their shoulders and say "Yeah, bfd, it's not the same, will never be the same, and you can't make it the same."
So gays can marry. Most heterosexual marriage couples shrug their shoulders, and say "bfd." "It's still not the same, and will never be the same. The Rubber Stamp Court can't make us accept you as our equals in this matter."