Not answering your question directly, but the homeless crisis in the US seems to have hit the radar in the early 1980s.
Part of that may be changing terminology -- earlier use of "homeless" tends to focus on "people made homeless" (or "... left ...") after some calamity: structure fire, flood, hurricane, etc. In the 1980s "homeless" became a chronic condition. Other terms may have existed for the long-term unhoused. I'm not aware of them.
What specifically changed, I'm not certain, though circumstances leading to the role of real estate as an asset rather than a utility may be part of that.
They're arguing for the removal of regulations in a general sense, not just specific problematic regulations. The solution being proposed is incorrect, regardless of whether the problem has been correctly identified.