It was your comparison, not mine.
First, I don't think a piece of paper makes a couple more legit. Second, I've said, time and time again, that I'd prefer to review the possible implications. Third, it took 100 years for a black man to be able to eat at the same table as a white man.
With this in mind, I think a gay couple can wait another day or two before getting married. If they can't, maybe they shouldn't get married. It would never last.