Almost all of them are gang related--YAY drug war! As an upper middle class software engineer it's not really a good argument.
Though the poverty and hopelessness can be a little sad if you walk through the bad areas.
I'm not saying life is bad in San Francisco, those statistics are just one part of the equasion. (the other parts: leaving behind family, friends, the good life I already have etc)
I am just against the notion that propping up that random incompetent guy (at least to some degree, so he wont roam the streets doing crazy stuff) is always a bad decision.
Preventing those people from failing miserably (and the negative side effects that come with it) - thats basically why we have a lower income over here.
And my pricetag for giving up all that is higher than just doubling my income.
http://en.wikipedia.org/wiki/United_States_cities_by_crime_r...
San Francisco has more homicides with its population of ~800k than all of Austria combined with a population of 8,5 million.