I was there a few months last year and this seems like nonsense. To me it seemed like all the homelessness was restricted to a few streets like in skid row.
When I first visited in 2011, near the Moscone Center, I saw dozens of homeless and a naked guy in a biker hat while heading to my hotel. Human shit and drug needles on the sidewalk. Last year, I am not sure I saw anything, but I was closer to the pier. It did stink like sewage on a couple of streets and nobody seemed to care.
It's worth noting that San Francisco has a long tradition of public nudity, so the naked guy probably shouldn't necessarily be included here, unless there was another reason to do so.