And here is another article, this one from 2009, on why “privatizing marriage” will not live up to its promise.
One proposed solution to the divisiveness of the same-sex marriage debate is to have the government get out of the marriage business altogether. This proposal is appealing because it seems to remove marriage from the realm of political contentiousness. We could mimic a market-type solution, in which individuals can make their own decisions about the meaning of marriage, and we need not make any collective decision. But these appearances are deceiving. We need to think through what it actually means to say that the government should “get out of the marriage business.”