Half of the homeless people in that Seattle video someone linked above should have had a roof over their heads provided by the State, either some mental-health institution or an elderly care house.

I've heard of way too many US ok-ish jobs that don't provide adequate health-insurance (just to give an example). Maybe I'm a little paranoid but I'd have constant nightmares thinking that a couple of days of hospitalization for a benign medical intervention could set me tens of thousands of dollars in debt (or worse).

I think what he is on about is the fact that even if the US has the safety nets you describe, it apparently isn't working.

He/She should have said that then.