The biological origin of pair-bonding is recognized. Exceptions to it are not considered 'momentary pair bonding', for example.
A modern state should certainly be able to formally recognize pair-bonding between members of opposite sex while excluding other arrangements without a clear biological origin.
Ergo, the folks advocating gay marriage, and even polygamy, are luddites and flat earthers.
I am supposing you intended to insult me by calling me a Luddite, or perhaps this was unintended. Just like piling all kinds of benefits unto those who copulate and denying them to others who don’t, wasn’t intended to discriminate against gays, but just did.
The Supreme Court has differentiated the discrimination suffered by gays (and by women and immigrants) from the discrimination suffered by blacks, saying discrimination against blacks was invidious, while discrimination against gays (and women and immigrants) didn’t reach that level. The discrimination against gays was mostly, if not totally unintended. Still, there it is.
Conservatives sought to improve on what nature gives us as marriage and wound up - possibly - violating the 14th Amendment (we’ll see what the Supremes say), and destroying marriage.