Professors are self-proclaimed intellectuals who are failures in the professional world.
While the supposed job description of a professor entails teaching, in actuality most professors know absolutely nothing about teaching. However, many professors will not hesitate to take a student's tuition money, not teach him anything, and then test him on what he was never taught.
The other main activity of a professor is embezzling money (that could have been spent on useful things) for their own "research". Usually, this "research" involves topics that nobody outside of academia will ever care about or find a practical application for.
Take solace in the fact that your professors earn a miserable salary in proportion to the level of education they have attained.
Professor Jones appropriated $100,000 to research if the poor performance of his class was due to his own incompetence. The results were inconclusive.