[pyrophane]

I agree with one of your points: that dealing with homelessness on a municipal level is problematic. It disincentivizes cities from providing extremely good care for its homeless population for fear that it will just attract more homeless people. There are already US cities whose answer to the homeless problem is to buy them a bus ticket to a city where they will be better cared for.

I do, however, think you are being a bit naive with respect to the notion that people are "keeping" the homeless in SF. The city's homeless population chooses to be there, for various reasons including SF's fair year-round weather and the fact that some have a connection to the city going back to before it was the tech-center it is today.