The interesting question is "Why don't you fools just go hire on at a union outfit?"
My answer would be because the industry colluded to make it extremely painful for somebody like me to change jobs within the industry.
I'm at top rate, have the earliest peddle time, never work the dock, get solid hours, my own pump jack and dolly, seniority for vacations, etc. Hell, I have my own dedicated tractor in a city bid. Nobody else has driven it in three years unless I'm out for some reason.
I'd lose every single one of those things if I moved somewhere. I have a family, house, etc, and while I could make due with a certain amount less per week, I can't really work at night, spare, or take a pay cut and work 30 hours.
This collusion is one of the primary reasons we can't seem to hire experienced driver over here (at my termina), despite having desperate need. If they have experience, then they have seniority, top rate, etc.