OP's economic argument is pretty sound. 40-50 years ago you could buy a new house, get a solid blue collar job with a pension, and watch your house 5x in value over the next 50 years. Makes it very, very easy to settle down with someone and start a family.
In today's economy, even for the relatively well-off, home ownership is essentially a pipe-dream and it is much harder to put down roots of any kind.
The second the marriage becomes hard, it's a lot easier to break a lease than it is to break a mortgage.