My wife is a Primary teacher, teaching prep. Leaves at 8, rarely home by 6 and the school is 10 minutes away. She has to do yard duty at recess and lunch more often then not. Personal development after school one night every week, with a staff meeting another night every two weeks. She would have a pupil free day once a term at most and report writing twice a year, which is done in personal time, takes at least 30 to 40 hours conservatively. Add in parent teacher interviews etc, and she's putting in well over 50 hours a week.
All that for what amounts to a modest salary. With all due respect, you have no idea what you are talking about.