I guess we could just treat all people equally, whether married or not.
The problem is that we offer tax benefits, social security benefits and special treatment to married couples because we need children to continue as a society. Homosexuals are incapable of naturally reproducing through sodomy, or any other sexual act between same sexual partners. Marriage isn’t about couples, it is about protection of children and the rights of children to be raised in a stable unit with a mother and a father.
Everything that the Leftists do attack the Civil Society by attacking the building block of society, the intact nuclear family. They promote no fault divorce, co habitation, single parenthood, and homosexual activity including codification in law that homosexual acts are as important and meaningful to society as the reproductive act. It is simply not the case.