I have no doubt that your teacher friends are outstanding examples of the teacher profession. But are they representative of the teacher population? If they were the kind of teachers that didn't really give a damn, and were just counting the days before retirement, would you have them as friends?
The point I'm making is that a person's circle of friends are people who generally are compatible with that person's personality and viewpoints. We tend to have as friends people who are in many ways like us.
As far as I know most of the teachers in their school district work the same. Lots of prep work and evening work. True, there probably are those who are just counting days to retirement. Not all teachers are dedicated.