It could be about validation. Although there are benefits that married people have access to that non-married people do not. <link>

That is not necessarily true. Gays can get many of those same benefits, depending on the state, by default like married couples. Anything missing can be done via legal documents.

For example Estate inheritance. Yes if there is no will the spouse gets it, but this can easily be solved by getting a will. Even married couples are encouraged to get a will as a precautionary measure. This idea that married couples get "extra rights" is over exaggerated.

The gay marriage issue is all about legitimizing homosexuality- that is it. Gays don't just want to be tolerated, they want children songs, and coloring books , and parades... wait they got parades. Speaking of which is there a hetro parade anywhere?