Some of the things that teachers (and by extension here I'm also talking about professors) can seem a little petty. In my experience however, if you act like a doormat, students walk all over you. Some of my students have a very poor attitude to punctuality. Constant interruptions as you begin a lesson are very disruptive, both to me and the other, punctual, students in the class. When I teach A level and students have chosen to do my course, I basically have the rule that if I have started teaching, they are not allowed in. This tends to mean that Students are not late. Conversely some of my colleagues are not as draconian and they spend a lot of time moaning about late students.
I agree with the grade thing though. In the end, the grade you achieve should be the grade you get. However I have a great deal of sympathy with the professor who docks a grade for each absence. It is very irritating if someone is constantly missing lessons. It can lead to borrowed/lost notes or being asked questions about things in previous lessons when the rest of us have moved on.
As for the what does it say about your teaching if someone passes a course just reading the notes and not listening to the teaching comment: Some students are very clever and could probably do it all by themselves. Unfortunately for them they have signed up to a class where the vast majority of students do need the teaching. They should either change course or put up with it. Putting up with it means being respectful to the professor and not impeding the learning of others.
Sir, well said. Well said indeed.
