Gay Marriage: Why is this an issue?

According to exit polls in the last US election (as reported by the New York Times) half of all gay people in the US don’t care about gay marriage:


Only about a quarter of voters surveyed in the national exit poll following the election favored same-sex marriage, and interestingly enough, only about half of gay and bisexual voters did.


(I had this in my draft articles section for ages, kind of forgetting about it. I saw it today and thought what the heck, I’ll throw it up.)