Another thing that is never discussed is that many of the schools relying heavily on adjuncts, including a lot of community colleges, face increasingly tight budgets. This literature (there are enough such articles that it is a literature) tries to give the impression that wealthy schools like Harvard are taking advantage of individuals that have fallen on hard times.<p>In reality, a lot of adjuncts are, as you point out, professionals that do this on the side. Still others are not looking for full-time work, but want to maintain a connection to the academic world.