I think about it like this: Let's say we have a hypothetical town with 100 residents.  Out of those 100 people, 5 are homeless.  The other residents walk by these people daily, but it's not long before some start taking notice and think "Hey, I can help this person".  So people pitch in, find shelter for these people, develop avenues for the homeless to get back on track.  3 of those 5 people do great, and get back on their feet.  One person has mental illness and gets the help they need, and finds appropriate housing where they can be cared for.  That last person though, they have no interest in trying.  The opportunities are there, but they just can't be bothered--'f*ck the system' they say, meanwhile continuing to use the systems set up to take care of them to their advantage.  And so it goes in that town, the other 99 residents shrugging their shoulders and saying 'ok, not a big deal'.  That would be just fine, should the town always remain at exactly 100 residents, but...