The real question that we are asking is: "how does this affect society? Does this have a positive, unifying affect on society, or does it continue the breaking of society into special interest groups? Is it "fair" to denigrate a long-held societal more based on religious beliefs in favor of a secular "religious" more?"
But don't we tend to argue against a societal benefit on other conservative issues? If I'm going to favor an individualist philosophy I guess I need to find some consistent place to draw the line. When does a societal argument make a good basis for restrictive laws, and when does it not?
As far as government recognition of any marriage goes, today even, aside from the gaystopo's need for social victories, it is about who gets what benefits and legal protections. It really isn't much about holy matrimony. I'd like to end government sanctioning of it altogether. But realistically, we not going to get rid of that legal construct. So I think I'd rather see marriage replaced with civil unions that has nothing to do with matrimony at all. I know of some elderly sisters who live together in order to pool their resources. I seriously doubt there is a sexual relationship there at all. They could benefit from the kinds of tax considerations and legal protections that married people get. Why does a couple need to have a sexual relationship and be wed? Why can't they legally form a civil union? Let marriage be about what it's always been, and separate that from government sanctioning altogether.