It's worth noting that a non-trivial percentage of homeless individuals are considered mentally ill, which generally means that society has, for better or worse, deemed them systematically incapable of making appropriate choices.

A lot of the homelessness problem in the USA came about from the big deinstitutionalization push in the 60s that... didn't really work as intended. Policy on homelessness since then has mostly been built around "make them go somewhere else".