Because the city and the electorate lack the will to deal with the problem vs doing little feel-good things that dance around the edges.
The current solution is put a "Twitter" in a bad area and construct new buildings around. So far seems is working.
I can say that people here are the most friendly ever seen so far (I'm european and I traveled a lot Europe, can't say about others places in the us).
So, I fatigue to think that San Franciscans are "bad" and they left most behind.
IMHO part of the problem is an heritage of and old lifestyle (especially with drugs).
What really upset me a bit is that here these people have no social care for their mental issues. Some are quite dangerous and I got really scared few times when I lived in tenderloin.
Plus, you think that most are by choice. However, you also point out lack of support for mental issues. I personally find this a contradiction – if you've got serious mental issues and no support, then the ability to choose is basically void.
I would really (ideally) like the urban BART stations to have restrooms, but unless the authorities are going to make sure they are clean, safe and sanitary, that's not going to work.
Homeless people were using the BART escalators as restrooms at night... causing them to break down. The solution? Multi-million dollar covers to stop people getting down there at night – not a considerably smaller sum for public restrooms.
This speaks to the psychology. There is still a population in SF that believes homelessness is a choice. And that facilities encourage homelessness. There is another segment that believes SF already shoulders a disproportionate amount of dealing homelessness. There are a lot of people that just find them annoying.
I'm always surprised how many locals don't believe Civic or Tenderloin is ever going to change. Why? Zoning, regulations – but mostly because it's always been that way.
So, yeah. I don't quite understand it either.