i played in several bar bands over the course of about twenty years, for "beer money" but there wwas always enough to take some home, and it actually was a useful extra income. i was married for most of this time and had four kids to feed. had i been single, i could have lived on it.
established artists really don't make that much more (they do, but they pay for a lot of services that whittle the take down to less impressive values). some artists or acts obviously command a higher price, but many of the financially secure artists also work for hire, either as studio sidemen, sound engineers, producers, etc, which might indicate a need to put bread on the table as much as creative genius.
playing music isn't an oilwell or a goldmine, but if you need to play music, may as well do it.
as a kalamazooan who has not personally had dealings with t&j, i've heard nothing at all good about them. i know at least three people who had their cars moved despite being legally and properly parked. i believe they have a contract with wmu, and get the bulk of campus area towing business.
i don't think that anyone's car should be towed for improper parking until a ticket is issued by an accountable parking authority.