The trouble though with this view is it always acts as though neighborhoods are static and unchanging. But any large City that's more than 100 years old sees neighborhoods rise and fall economically and/or change dramatically in a social sense over time. Sometimes for the worse, sometimes for the better. When you "protect" these neighborhoods with artificial controls you just end up extorting all kinds of outcomes which are never healthy. The tenant on this FB post is like a Frog in slowly heating water with no sense of temperature. By the time she realizes what's happening it's too late and she's seriously stuck. If the rents in her area were going up 10 - 20% or more every year (and hers along with it) the shock would be less and she'd plan ahead to move.