from OP's tone I'd guess personal experience - I lived in one in my late teens/early twenties (Alberta still allowed them at the time, maybe it still does IDK). We had a guy attempt suicide in the kitchen one night. I heard after moving out that another roommate I'd been friendly with got kicked out after relapsing and getting 'back into the crack', according to the landlady's boyfriend.

It is a fact that criminals and addicts will flock towards the cheapest housing options and bring their problems with them. That's just the nature of being the cheapest option.