it's sort of like anything else.

If I hate my pay, I'll look for a job elsewhere that pays more... well, that's not true. I have no motivation to do that, but it would be on me to do that if I hated my pay.

THe competition for teachers apparently doesn't drive up the cost of teachers like it does in some fields.
Some people have a weird notion that people should be paid based on training or education or whatever. That's nuts. A person should be paid what the economy demands that person is paid.