I suspect you aren't familiar with NYC from the 70s through the mid 90s. It was as bad then as SF is now. Giuliani completely transformed Manhattan and made the streets and parks usable again, and they stayed that way for a while. It's going downhill fast, though. Penn Station and Port Authority are turning into shooting galleries again, there are encampments growing, bodily waste on the sidewalks, and plenty of harassment. Give it another few years of hands-off policies and it'll be as bad as the west coast cities.