Go re read you research, if in fact you did any. As I believe was said earlier, we have a maral issue we stand by here in this country. Also, any child who lacks a mother or who lacks a father, feels an empty void due to that missing parent of the other sex, male or female, mother or father, all their lives, and overcompensates in sometimes distructive ways to fill that void.
In fact, that is the main reason, when children are adopted they feel the biological need to find their birth parents, and when a divorce takes a parent away from that child, they are compelled to find that parent later in life. To have both parents is a biologically "normal" state of life. That is why you have so many saying marriage is about children. FACT
I think you're missing my point, which is that the existence of government-issued marriage licenses has no inherent connection to whether a child grows up in a home with the same two parents all along the way. Married couples who stay together and raise children together are doing so because they want to -- they would not abandon their lifestyle if the government stopped issuing licenses for it, or starting issuing licenses for for other family arrangements. Given that the government-issued licenses accomplish nothing, and are intrusive into the lives of free citizens, they should be discontinued.