Why are some teachers so hard headed?

Question

The bell always rings at 9:50 to switch class. Today, the bell was turned off due to testing but the schedule was still the same. My teacher forced us to stay in class until 9:55 because he believed that that’s when class changes even though I told him no, it doesn’t. All the other classes were leaving except for mine. What a dumbass. 

Answer 1

We had teachers do this and would say "I dismiss not the bell" we would be late to the next class and the teacher would say "the only class I care about is mine" or "be here on time" and get tardies. Though arguing will just make the problem worse

Answer 2

Class is over when the teacher says it is, and students leave when they're dismissed, not before. 

Answer 3

Gee, I am so sorry that your life had to experience 5 minutes of inconvenience. You are precious and don't deserve that kind of torture.