I don't know, I think the erosion of marriage began before same-sex weddings were even an issue -- and a continual erosion of marriage will certainly not be sue to same-sex weddings being an issue.
Everyone would shut up if we just took away all governmental benefits from marriage period, then the gays wouldn't be able to complain, and marriage, a traditon that IS held sacred by the churches (and always will be), would not be seen as something as trivial as receiving social security benefits for whoever is involved.
Nicely put. I think no-fault divorce laws had something to do with the erosion of marriage as well...