this. there's almost no fiscal incentive to even BE a teacher, let alone a well-educated one.

Well, the way you get instant raises in the public school system is by completing more advanced degrees

When you overpay teachers, people who hate teaching, and hate being teachers, will become teachers for the money.

Is a good idea to select the people who hate teaching to become teachers?

They're already paid better than adjunct professors or grad students which is the normal career path for people with advanced degrees.

Fwiw, in 1900 my grandfather taught school in Washington State. He was 16 years old.

I don't know how good he was, just saying it wasn't so long ago.

It depends on the grade though: no degree would probably be fine for a kindergarten teacher, but I'd be a little concerned if a high school math/science teacher had zero post-secondary experience, especially if this were at a school where most students are planning on attending university.