That said, if the market falls it is easy to end up with a mortgage that costs more than rent, a fact that I am unfortunately familiar with.
Two case in point examples: Prop 13, and rent control.
These are not, as popularly concieved, great ways to protect the poor and disadvantaged. They are simply examples of very short term thinking becoming public policy, which has the unintended and paradoxical effect of harming the poor and disadvantaged much more in the long run.
What I'm saying is, if you want this policy, start thinking of ways you could change it while accounting for the harm that changing it would do.
The middle class will not be able to afford to live in the most expensive housing markets in the country. But that's the way it's always been.