"I see no damage in pointing out that the opinion was consistent with views currently held around the world. I don't particularly care but it doesn't hurt anything."
The job of the Supreme Court of the US is NOT to point out opinions from around the world. The job of the Supreme Court is only to determine the intent of the law of this land.
What law did Justice Kennedy interpret? Why did he interpret it that way?
The SC's job is to rule upon law and since NO law is created only by domestic forces but draws upon a long tradition of law outside the nation referring to foreign law violates no constitutional standard. Nor is this the first legal opinion which considers law elsewhere it is as old as the republic.
But you can get hysterical if you like.