I suspect these people have never actually lived somewhere nice and think junkies threatening you on the street is just normal background noise you have everywhere.
this kind of shit happens everywhere along geary and market stretching all the way past divisadero and to castro. there's a reason the tenderloin is right where geary and market come together. i lived in SF for 2 years around 2008 and it wasn't safe then either.
and more recently i've seen crazy shit go down (or the aftermath, like broken glass everywhere) every time i visit friends. the western more suburban parts of the city are much better.
sf has basically been broken since the gold rush. seems to me the primary goal these days is to make enough money to insulate yourself from this stuff as much as possible, or just leave.