AlbertC
Superstar
I think with SF its just more focused in the Tenderloin really. As I said, it may just be more visible in Toronto as there are no truly bad areas in the city where the poor tend to congregate. When I visited last March I came into the city by Ferry and the first thing I noticed when I got off the ferry was that there were no homeless hanging around the ferry terminal. (which is much, much busier than Toronto's ferry terminal, its more of a mini Union)
You're observing the city with tourist-tinted glasses. Similar to some people analyzing Chicago by what they see in the Loop but neglecting the overall big picture. I haven't personally been to San Fran, but a quick Google search results in already many articles depicting the struggles of poverty in that city.
Last summer I lived in Seattle and although I fell in love with the city, I couldn't help but notice the persistent homeless issues present there. A day trip over to Vancouver also revealed many of the problems there as well.