And what's killing marriage in France is straight civil unions. From the NY Times:
Whatever their reasons, and they vary widely, French couples are increasingly shunning traditional marriages and opting instead for civil unions, to the point that there are now two civil unions for every three marriages.Yes, but that part isn't available to LGBT people.
When France created its system of civil unions in 1999, it was heralded as a revolution in gay rights, a relationship almost like marriage, but not quite. No one, though, anticipated how many couples would make use of the new law. Nor was it predicted that by 2009, the overwhelming majority of civil unions would be between straight couples.
It remains unclear whether the idea of a civil union, called a pacte civil de solidarité, or PACS, has responded to a shift in social attitudes or caused one. ....
As with traditional marriages, civil unions allow couples to file joint tax returns, exempt spouses from inheritance taxes, permit partners to share insurance policies, ease access to residency permits for foreigners and make partners responsible for each other’s debts. Concluding a civil union requires little more than a single appearance before a judicial official, and ending one is even easier....
Though French marriages are officially concluded in civil ceremonies held in town halls, not in churches, marriage is still viewed here as a “heavy and invasive” institution with deep ties to Christianity,...
For some, civil unions are simply a form of premarital engagement. Ms. Anicet, the student, said she and her boyfriend would probably be married were they not of different religions. She is Catholic, he is Jewish, and his mother disapproves of marrying outside the faith, Ms. Anicet said.
“We’re realizing that this is a test,” she said, “a way to get our families used to it.”
Though the two had considered a civil union for tax reasons, now “it’s a jumping-off point to getting married, later,” she said, adding after a pause, “I hope.”
It's deliciously ironic that by forbidding LGBT people access to marriage, the civil unions undercut marriage.