Violent crime is rare everywhere, for some definition of rare. I can walk through the most dangerous part of Chicago tonight and I will almost certainly survive. However, if I do that every night for my entire life, the cumulative risk will be unacceptably high.

It would be wrong to insist Chicago doesn't have a problem with violence just because I have much better than Vegas odds of not dying today. SF has different parameter inputs than Chicago, but my point applies.