Admiral Percy Fitzwallace (John Amos): The problem with that is that's what they were saying about me 50 years ago - blacks shouldn't serve with whites. It would disrupt the unit. You know what? It did disrupt the unit. The unit got over it. The unit changed. I'm an admiral in the U.S. Navy and Chairman of the Joint Chiefs of Staff... Beat that with a stick. "Let Bartlett Be Bartlett." The West Wing (2000).
The topic of this scene was gays in the military, but it could easily have been about same-sex marriage. Arguments in opposition tend to offer, among other things, that it would be a disruptive influence on society. People would become confused.
The Supreme Court this week, without comment, let stand several Federal Court rulings that favor marriage as a constitutional right for all. Motives for why the justices so decided are easy to ascribe - countless legal beagle pundits have offered to fill in the blanks left by the Court. Since none of these scribblers know for certain, they are only guesses. So my guess is as good as theirs.
My guess is that they saw no particular reason to hear the cases. Not every social or cultural disagreement requires nine lawyers, no matter how accomplished they are, to add their voices to the discussion. The lower courts have heard the witnesses, weighed the evidence and ruled in favor of freedom.
Sometimes one can make the loudest comment by choosing silence.