There is a huge market for rough, indie, bluesy, jammers that can just rock and look like they've lived in the streets and shit...
He could do exactly what he did in that vid in any small bar across the country and easily make $100 and a couple free beers / meals per night for a couple week run...But he would have to have a solid repertoire to be able to jam for 5 hours straight from like 9-2am or so.
Also needs a chill drummer, and a basic bass line just to round it out and be able to play some other shit, I could see him ramblin some Nirvana covers...Alice in chains etc. at some bar, easily has the character in his voice like he's lived a hard life.
People want musicians to be rough and edgy not perfect little spoon fed pussies, gotta have scars and a few missing teeth to really intimidate people into realizing that they couldn't do it themselves, it's a persona, a certain aura around a real rocker that takes a hard rough boozin and druggin hobo life to really sell..