And the dogs have rubber teeth…
And the cops have wooden legs…
I think it has more sinister class-stained origins: for some reason, rich and well-off white people don’t like poor white people, don’t enjoy having them around, or want to see them or have anything to do with them, so rich white people won’t hire poor white people for casual or day-work if there’s anyone else available for hire.
Maybe.
In my bro’s case, rich is not him, not even a little bit. He’s been close to homeless a time or three when business turns down.
The man with one run-out raggedy pickup may be better off than the man with zero run out raggedy pickups, but that doesn’t make him “rich”.
Homer: I married her!
Is Reacher a Hobo?
Naah; more of a walking killing machine. That’s a whole 'nuther category. 
He’s more of a Knight Errant.
A modern Paladin, who was himself a modern Knight Errant of his time.
Have gun will travel, reads the card of a man
A knight without armor in a savage land
But Paladin did have a home- a hotel in "Frisco. IMHO- one of the best B&W western TV shows.
I didn’t say Paladin was a tramp or a hobo-- I said he was a knight-errant, in response to @Alessan.
As far as I know there’s nothing in the definition of a ‘knight-errant’ that says they can’t have a home base when they need a break from seeking out virtuous adventures.
Agreed. Script writers included Harlan Ellison and Gene Roddenberry.