those are good ideas but imagine someone barely making ends meet on an "inflated" mortgage which then loses a lot of value. the bank expects them to pay back $250K but then their home value collapses down to its true price of $150K. you just created a situation where a household has negative equity - literally worse off than if they had never bought the home at all, and difficult to wiggle out of if they live there (very likely). that obviously has massive effects on their economic outlooks.
Yeah, this is absolutely a problem and people's homes being foreclosed due to this type of situation does upset me. But this is a side-effect of people making money off housing shortages, which is the root cause and due for a correction.
The people with these AirBnbs are no worse than the residents who vote for policies and politicians that create and exacerbate the shortages in the first place.
