Because the unions carry legal consequences, and are therefore the purview of the state.
That having been said, one could imagine that a government that didn't evolve from a religiously-knitted culture would have grounded those unions of family more firmly in contract law, not in a construct that's bound up with gender requirements.
... and when you can find such a government on the entirety of Earth, let me know. ;)
That having been said, one could imagine that a government that didn't evolve from a religiously-knitted culture would have grounded those unions of family more firmly in contract law, not in a construct that's bound up with gender requirements.
... and when you can find such a government on the entirety of Earth, let me know. ;)