"The other setting is Urban, you don't know neighbours, you don't care what they think. Everyone appears out of nowhere and disappears into obscurity."
And yet crime levels in various urban settings are wildly different, from places like Johannesburg on one extreme of the continuum to Reykjavík or Tokio on the other one.
Looking at the worst cities worldwide as far as homicide goes, almost all the top contenders are from Mexico, South Africa, Brazil, the US or Colombia, with Mexico being heavily overrepresented. 17 of the top 50 homicide metropolises are Mexican. Damn.
There isn't a single European or Asian city in that list. Germany has some 60 per cent of the Mexican population, but isn't present in the top 50 at all. Heck, even India and China just aren't there, and they together account for almost half of mankind.
https://en.wikipedia.org/wiki/List_of_cities_by_homicide_rat...
The pattern is too non-random to claim that urban life in itself is somehow inherently dangerous. It is only dangerous if your governance sucks.
And yes, SF governance sucks, though not to the degree of Ciudad Juarez - but that is a low, low hurdle to clear.