The well-meant and originally-necessary drive to end criminalising poverty overcorrected into absurdity by equating poverty with mental illness, and compassion for the mentally ill with not arresting people who smear feces over restroom walls. This fallacy, which dovetailed with anti-police sentiments, is most pronounced in San Francisco. But it’s also present in other American cities.
The toilets and piles of human defecation rolling down the hill are a consequence of the above, and unsolvable until the above is addressed first. You can't borrow ideas from other cities around the world because those don't have rampant inequality.
of which services are funded by and voted in by taxpayers.
So yes, to some extent it is the people's fault.
Except it is a similar problem in most cities?
The only exceptions are cities with nasty weather which basically "solves" the homeless problem every winter or cities which basically shuffle the homeless into jail.
I haven't really seen any big city (even in Europe) "solve" their homeless problem any other way.