Problem is there is no comparison in the public sector where you can compare teachers salary with another position in industry. Teachers work doesn’t end with the school day. I’ve helped my friends in the evening going over the tests, homework kids turned in. They have spent several hours before class and after class. Again, they get a fixed salary and it’s up to them how they want to receive it; either in 12 month segments or 10 month segments. They do not get paid a years salary for just ten months work.
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.