The fact is it can't just be SF's problem, because SF is a magnet for homeless people from all over CA and the US. That makes it a US problem, and yes, it is a disgrace.
Homelessness is a crisis that is growing all over the US.
Homeless crisis in Hawaii sparks state of emergency http://www.cbsnews.com/videos/homeless-crisis-in-hawaii-spar...
L.A. County supervisors call for a state emergency declaration on homelessness http://www.latimes.com/local/lanow/la-me-ln-homeless-emergen...
Mayor, county exec declare ‘state of emergency’ over homelessness http://www.seattletimes.com/seattle-news/politics/mayor-coun...
2. The weather in the Bay Area makes us a target for homeless people everywhere.
3. Related to #1, but different: not being "anti homeless people" is a reason people come to SF and Berkeley. I don't this is the same as encouraging homeless people to come to SF and Berkeley.