Do you actually think people in other professions actually only work 40 hours per week? Grading papers versus researching an environmental issue and staying up late writing a report with a short deadline. Attending meetings at night dealing with a pubic life safety threat. In the office late preparing for a critical court case.
My sister always made the "but I have to bring papers home to grade" argument. To which I would say, "oh yea, well we were out till midnight in 32 degree weather working on a water main leak in the cold & snow so people can get their water turned back on. It's always as if teachers are the only ones putting in overtime.
In addition, teachers aren't the only ones who spend their own money on supplies and resources for work.