You see all teachers go to school, or just the teachers at one particular school? You watch them every single day?
None of the teachers get there more than 30 minutes before the students? All of the teachers leave right after the final bell? Is this a bell for students or for teachers? At our school, the last bell rings 35 minutes after the students leave, to tell the teachers they may leave then if they wish. Some do, many don't.
Do you notice whether or not the teachers are carrying anything when they leave, such as papers to be graded at home? Do you know what the teachers do after they leave school?
Especially when my children were small, I left school when teachers were dismissed to be with my children, but after my children were in bed I frequently worked until midnight or later grading papers or planning.
Do you think all teachers are like the teachers in this particular school? Do you have any evidence to back up any of your contentions, or should we just take your word that you have nothing to do most days but watch the teacher parking lot at some school?
I did not watch every teacher at every school. Nor have you. Your contention was that they work 15-18 hours a day. I said not the ones I see. Not the ones I know.
So which is it? Are they underpaid and overworked of overpaid and underworked?