For a bit of a more balanced discussion of some of the key points related to SF's housing problems, you might want to read Kim-Mai Cutler's (very long and very good) assessment of the issue:
I don't even want to pick out any quotes because that would be doing it a disservice, but I think it argues successfully that many of the displacement and culture problems surrounding SF today are, at the core, housing issues. And the blame for those problems does not lie solely with tech workers, and the potential solutions are far deeper and more complicated than all of us trying to "not being awful" (though not being awful is a good start).
http://techcrunch.com/2014/04/14/sf-housing/
(HN discussion: https://news.ycombinator.com/item?id=7590250)
I don't even want to pick out any quotes because that would be doing it a disservice, but I think it argues successfully that many of the displacement and culture problems surrounding SF today are, at the core, housing issues. And the blame for those problems does not lie solely with tech workers, and the potential solutions are far deeper and more complicated than all of us trying to "not being awful" (though not being awful is a good start).