Earlier quoted context omitted.
I own a condo too. And if I move I probably won't sell it, but rather rent it out until I move back (while living in a rented place of my own). Individual home ownership is not a problem, it should be encouraged. The problem is people (and REITs) who lever up with a bunch of properties to be fed half of people's paycheck in the manner described. I will nitpick and say that paying your mortgage is not a cost. That is…
You are very confused. A mortgage is definitely a cost. It's only meaningful equity if you ever sell it and get any of the money back, which is not guaranteed at all. And only public housing would collapse the entire economy. Plenty of countries tried this, most notably the commies in Russia and in eastern Europe.
However, as someone who's lived in a large urban area with public housing - I can confidently say that the only real benefit public housing has is reducing the price of high end real-estate in close proximity and increasing petty crime in the area.
Source - lived in the South End neighborhood of Boston proper.