I'm inclined to agree with you. Gay Marriage isn't a civil right's issue, it's a solution to a set of civil rights issues. Legalizing gay marriage doesn't help the child raised by his mom and an unrelated "auntie" who can't visit the kid in the hospital. It doesn't help the two best friends who have been living in a non-romantic domestic partnership for 20 years who can't both live and work in the same country.

I would prefer if we just make it illegal for anyone (IRS, immigration, employers, etc) to discriminate based on marital status. Problem solved.