This is a gross oversimplification of the author's detailed (if a bit editorialized) analysis. The author actually acknowledges, and later expounds upon, the apparent incongruity you mentioned:

> I look at communities like Detroit and I understand why the youth there resort to crime, but what the hell is the matter with the Bay Area? Arguably the wealthiest metropolitan area in the United States. A place with too many jobs and not enough people to fill them.