I'll confess to mixed feelings about Ted Olson joining the fight for gay marriage. On one hand, I'm glad to have him on the team, with the esteem he has with colleagues and his admittedly prodigious legal skills. But I fear that the more conservatives who get mixed up in this, the more likely it is that gay marriage is going to end up becoming a tool that's used to justify continued de-privileging of people who can't or won't get married for various reasons, including asexuality, non-monogamous inclinations expressed honestly, loner-ism, or political objections to the existence of marital privilege/enforced monogamy. But I'm setting all this aside to say that the fact that there are few Ted Olsons in the world is evidence of how full of shit most social conservatives are when they talk about marriage.
To explain why, I'll start with what I see are the three main reasons that the institution of marriage exists (which are separate from the individual reasons people choose to marry):
1) The subjugation of women.
2) Social stability.
3) Pleasure (this is a recent innovation, but so widespread that it has to be included).
Now that women are legally equal and even the biggest misogynists out there feel they have to pay lip service to women's equality, speaking about #1 is a big, fat no-no. Pragmatically speaking, #1 is still a major part of modern American marriage---women still mostly change their names when they marry, women take on more housework but make less money (while men see the inverse) after marriage, and women start giving free labor over to the care and feeding of men that results in better health outcomes for men than when they're left to their own devices.
Obviously, individuals in the flush of love still marry mainly for reason #3---both the wedding offer pleasure, and the fantasies of happy family life do as well. But the justifications for marital privilege are all about #2, the idea being that marital privilege is payment for creating social stability. I'm skeptical, for reasons I've hit upon endlessly, if for no other reason than the idea that you have to compensate people for marriage undermines the idea that marriage is worth undertaking strictly for love and commitment. In fact, this contradiction is all over our pop culture. We both suck up endless amounts of wedding porn, and then turn around and crack jokes about what a miserable trap marriage is.
Liberals generally put more emphasis on #3 and conservatives on #2, but I'd argue that most of us view marriage in relatively the same way---most people buy in for love, but also accept duty. The love arguments for marriage make same-sex marriage rights a shoo-in. But what's interesting about Ted Olson's argument is that, if you take at face value the claim that marriage is mainly about social stability seriously, then you also have to support gay marriage. Conservative attempts to get around this problem are laughable---they bring up images of promiscuous sex to horrify people, but of course if you're interested in promiscuous sex---regardless of your sexual orientation---you're not usually one to clamor for marriage rights.
But there is a way to be for #2 and not feel a contradiction when opposing gay marriage, and that's if you prioritize #1 over #2---that is, see social stability as a good, but the subjugation of women and policing of gender as the number one priority. It's possible for marriage to survive being remade into an egalitarian institution (though y'all know my doubts on this), but I'd argue that conservatives who are absolutely bonkers on this issue really don't want marriage if it doesn't exist precisely to police gender. But of course, they can't say that out loud---neither that they want marriage to continue to be defined by women's second class status, nor that they just hate gay people and want to lash out at them. So we get incoherent arguments, and I suppose that means we're going to see more people like Ted Olson decamp to the egalitarian side.
I do wonder if Olson moved over because he was a true believer in the arguments made by mostly disingenuous conservatives, or if he has gay people in his life that have made the discomfort with these disingenuous arguments more pronounced, because they're such obvious cover stories for bigotry. His article indicates that the latter is the likelier story. His arguments are shockingly egalitarian and kind-hearted in tone; it really made me wonder. Any way you slice it, though: Good for him.