I had a Calc II professor like that in college. He told us on the first day, "I don't take attendance, and I don't grade homework. If you want to pass the class you'll attend and you'll do the homework on your own."

Long story short, the vast majority of the class attended, did the homework, and still failed anyway. He was known for being... unrelenting and awful. If women went to his office for help during office hours, he wouldn't help them... one of those professors.