Here is a direct quote:
In a nutshell: It is an essential aspect of our Jewishness that we strive to be other-oriented rather than self-oriented. This leads us directly to G-dliness, or is perhaps a subset of G-dliness, as we strive to serve His needs rather than our own. By marrying someone who is wired like me (a male) or even someone not wired like me but nonetheless innately familiar to me (a female, but a close relative of mine) I will not become as other-oriented as I would had I married someone who is completely different than I am. (This also gives context to the linkage between feminism – ‘no differences’ between roles of men and women – and the gay lifestyle.)
Since they are known not to always publish comments which disagree [SECOND update: my comment now shows up there.], I'll simul-post my response here:
With all due respect, I find your rationalization utterly uncompelling. What you seem to ignore is that gay people cannot enter into a good marriage with a member of the opposite sex. It’s just not an option. (Please note that I specified a good marriage.) Clearly, by even your logic, marrying someone, even a member of the same sex, would make you more “other-oriented” than would remaining single. Forbidding same-sex marriage forces people to be LESS other-oriented, and so you should be against a prohibition.
Moreover, proponents of a ban on gay marriage seem to believe that if it’s forbidden, gay people will just go away or magically become straight. This is not the case. There are already gay couples who live together, have children together, and create families together. Banning gay marriages serves only to discriminate against such couples and their children and does not provide any benefit. [I added the next line to my post here for emphasis:] A gay marriage ban does not prevent gay families, it just discriminates against them. You must first recognize that gay families exist and then deal with that reality rather than assuming that if you ban gay marriage, gay people will just disappear.