To validate this and one of the above comments, you could give some people a free apartment with electricity etc. and they'd still screw it up badly. And it's often not even an obvious issue of mental illness, it's more described as just completely unsocialized, wild, a sociopathic level of disagreeability.
To be clear I'm not implying this is everyone, or that money wouldn't help, but it's complicated.
The CBC followed this one homeless man for a while in Toronto, he was given a $1200/month basement apartment for free. After a few months, he walked out, choosing to live on the street (in wintertime no less!). He complained that the carpets were 'dingy and musty and disgusting'. Now it wasn't really apparent if they were or not, but literally as he's saying this, the camera pans to the shelf where there are about 40 empty 'tall boy' beer cans.
I could only think that since he's not really doing anything all day, he could probably work out a deal with the landlord to remove the carpets if they were really that bad, or else, file a material complaint if they were, but it honestly didn't seem like it was an especially negative situation to begin with.
Also, it seemed that the homeless man was very cantankerous and antagonistic.
So just consider that nugget: 'carpets not nice enough for me so Ima rough it' is the logic employed here.
I mean, possibly the carpets were toxic, but I doubt it, moreover, any other reasonable person would find a way to fix the problem considering the 'glorious' opportunity of having quite a nice little flat in one of the more expensive parts of the country for free. But it ends up in argumentation, aggression, complications, and literally 'back on the street', by choice.
I wonder to what the degree of anti-social behavior is learned or is an adaption of 'street life' or if these types were always like that, and if som, does an excessive degree of anti-social behavior count as 'mental illness'. There's a really interesting degree of hyper-libertarianism going on there as well, that 'street life' at least implies a kind of 'absolute freedom' with no rules, no clocks, no responsibilities of any kind, no concept of social order etc..
There are some studies that delineate between the 'temporary and long-term homeless', it might be that it's really important to nab people as they are just descending into this darkness before all of those ugly social features start to encroach upon someone's identity and they don't come back from the mouth of madness.