OP is right, these neighborhoods exists. it's so hard to put your finger on, but you recognize it when you see it. it's not necessarily downtown vs suburb, some suburbs are just kind of foul too. Just this weekend, me and my kids saw somebody trying to put a syringe in his thigh (being tactful here). we thought he was releaving himself and were making jokes about it, until we actually got closer. It's bad out there.

Like, parks always have had vagrants, but there's a difference between the loveable wino napping away his hangover or skulking junkies trying to score. i don't think they're necessarily dangerous, but children are seeing things they shouldn't at their age.

btw - i still think it's cars, mostly, but it all depends on the details. it's sadly and and and and..