Look at how diverse current civil marriages are in the US. The range and diversity runs from Amish families with dozens of kids to yuppie bi-coastal childless couples on career paths; there are open marriages and arranged marriages; there is Rick Santorum and Britney Spears - between all of whom the civil law makes no distinction. The experience of gay couples therefore falls easily within the actual living definition of civil marriage as it is today, and as it has been now for decades. To exclude gays and gays alone is therefore not the upholding of an ideal (Britney Spears and Larry King are fine - but a lesbian couple who have lived together for decades are verboten) so much as making a lone exception to inclusion on the grounds of sexual orientation.
What, in other words, would Ross have gay people do? What incentives would he, a social conservative, put in place to encourage gay couples and support them in their commitments and parenting and love? Notice the massive silence. He is not a homophobe as I can personally attest. But if he cannot offer something for this part of our society except a sad lament that they are forever uniquely excluded, by their nature, from being a "microcosm of civilization", then this is not a serious contribution to the question at hand. It is merely a restatement of abstract dogma - not a contribution to the actual political and social debate we are now having.