In fact you are wrong. Sexual corruption didn't begin until Noach's time, hundreds of years after the creation of the world and Adam and the beginning of "civilization" as Torah Jews believe.
Regardless you're arguing over fine print instead of the point but you're wrong about the fine print as well. Let's see you answer that.
Your quote here:
A historical view that has held sway since the beginning of civilization. Not an enlightened decision based on popular opinion.
implies that sexual behavior has historically been between man and woman, and recently there is an enlightened movement that is popular so people are now pro homosexual behavior.
But what was shown is that for thousands of years and in many of the greatest societies in "history" held that homosexual behavior was the preferred way of having a partner you love.
So by saying that history would dictate that marriage should be between marriage (or sexual behavior) should be between a man and woman is simply inaccurate. And to imply that it is a enlightened (meaning newer and recent) movement that is pro-gay, is also historically inaccurate as it has a long history in this world and basis.
To broaden the discussion the Torah doesn't really comment on a marriage contract between two men, only about sexual contact, the court didn't rule on sexual contact, only on a contract which maybe the Torah does or doesn't recognize as having any halachik ramifications.
For example if yankel and shimon want tax benefits of being married does the torah forbid this? I do not think so.
That example shows the ruling of the court is not necessarily against halacha.
I do agree it is a break down of the morals and spirit of the Torah however.
Let's see you answer that.
That is how I would answer you in short. This can be talked about for days.