Tradition. All it means is "something that has been done by people for a long time." There's nothing magical there. We have done really smart things, and really stupid things, for a long time. We are human beings. What do you expect?
So those "traditionalists" who tell us we can't just trash 2000 years of the historical understanding of what constitutes "traditional marriage," we can't just redefine it on the spot, are basically saying, "We must do what we always have done, because that's what we've always done."
Kind of like a parent who answers their child's persistent question of "Why?" With, "Because I say so."
Sorry. Not good enough. Tradition is a lousy reason to keep a group of people down. It's a lousy reason to discriminate and oppress. And don't try to bring "God" into it. No one knows the mind of God. And those musty old religious books that everyone likes to bang on were written by men. Not Gods.
So, yes, let's make a new tradition, starting right now. Let's treat all people with Respect and Dignity. Equality and Freedom. For all.