Nope, I was never involved in the fast food industry. I'm posting what I've personally observed, both live and in print. It's not unheard of for a career that originally started out as great to start wearing on you after a few years. My dad retired 4 years ago partially because political bullshit quickly increased to the point where his job was no longer rewarding.
And if Josher and/or Shaun reach the frustration point in their food service careers, they've got experience they can easily apply to other fields. In fact, Shaun posted elsewhere about his criminal justice classes and mentioned joining the academy sometime in the near future to begin his law enforcement training. Since Josher is only 18, I'm quite sure his career will change at least once within the next 15 years.
In closing, they will both know if/when it's time to change gears, and then act before it's too late. Gill, a.k.a. Trolley Dolly did just that a few months ago, and says she's enjoying her new career. As for David and The Ghost, they have a right to their opinions, but they do get quite theatrical in my opinion. Basically, they seem to be good people however. Myself, I'm not going to let the nature of many of the "suits" get to me. My throwing myself into a rage will change nothing.