Non drivers rarely hear this comment. It has many meanings. It can be a greeting, or a comment of disdain, or simply babble, depending on the circumstances and the tone of voice. When I get out of my car and start walking through the lot to start a shift, I frequently say to the first person I walk past, "Get a job."
The usual reply is, "I got a job." This is a way of saying, cab driving is a job, it's my job, and that's that. The second most common reply is, "I don't wanna."
We sometimes speak of this thing called, "A real job." I got one of those a few years ago. It sucks. It sucks the fat off dead bears butts. That said, many of my fellow drivers, somewhat envie me, I have health insurance (it's worthless), I get paid vacation days (which I schedule on football Fridays so I can drive cab), and I get sick leave (which I'm only supposed to take if I'm dying). In short, any real job that a cab driver can get, is probably over rated. There are exceptions, not many, but they do exist. I told my supervisor, at my real job, that I've had enough of it in general, and I'm going to leave in February (Why February? Perhaps I'll explain that in a later post. The crap that goes on at real jobs is too outrageous to be real sometimes.)