"San Francisco boasts superb weather. ... There may be some fog, or a bit of rain from time to time, but most of the time it’s sunny and hovering around the high 60s to lower 70s."
and a closely-related bad point:
"the sight of homeless persons in varying states of dishevelment".
If you're homeless, being so in a spot where it's nearly always comfortable to be outside is perfectly sensible. It's not surprising that there are fewer homeless people in areas where it snows and freezes.
His link to http://emptyage.honan.net/mth/2009/07/are-you-going-to-san-f... is well worth following, particularly for the good advice:
"If you're moving 3,000 (or even 300) miles to live in San Francisco; live in San Francisco. And by I don't simply mean that you should not live in the East Bay or the Peninsula or Marin. I mean live in a part of the city that your great-grandparents would recognize as being San Francisco. Somewhere that was entirely residential, and all of the homes in your neighborhood existed, prior to 1915."
The old neighborhoods of San Francisco are wonderful, with considerable village character, nothing like living in SOMA or the Tenderloin.