But anyway ... there WAS a point relative to the thread. Scalia wondered about the effect of gay marriage on the kids.
We have a ton of experience with the effect of traditional marriage on kids.
So I believe the point had something to do with redefining traditional marriage to satisfy a certain population demographic when, in truth, the demographic in question can enter into contracts with each other any time they want without redefining marriage for everyone else.
HOW does same sex marriage constitute "redefining marriage for everyone else"?
What harm ensues to opposite sex partners if same sex marriage is legalised across the country?
Just last month I attended a relative's marriage to his partner in Maine. Very nice, family occasion for the families of both men. For some reason or other, none of the hetero couples in attendance have decided to divorce and go for a same sex partner.
“And I have no doubt that every new example will succeed, as every past one has done, in shewing that religion & Govt will both exist in greater purity, the less they are mixed together.”
~ James Madison, letter to Edward Livingston, July 10, 1822
I agree with how you framed Scalia's remark, and would even go further and say that any reasonable scientist should agree that it's an open question. If it were a settled issue it wouldn't currently be the subject of so much research.