Millions of homeless people in hundreds of other cities around the world suffer from the exact same conditions you've described. Yet nowhere but the Bay Area have I seen those conditions caused those people to behave the way they do in SF. The city has spent hundreds of millions of dollars on safe injection sites, needle disposals, and public restrooms, and yet still must continue to spend money to pay city employees to clean up needles and human waste from the streets and transit stations.

Homelessness is a massive problem in SF, but the attitude that they behave this way "because of the situation they're in" is untrue and counterproductive.