guerilla love made a good point about the degree solidifying a place in the job market, but the informal "knowledge bank" is just as good. It depends on what is important to you.

There are some professors, however, that are "rebels" in their own right. They "use" the university and its classes as a medium for their message. Then again, there are others whose primary interest is research, and they only teach because it's mandatory. You gotta get lucky or get a good reference...which still requires some luck.

Good luck.