It’s not really surprising that teachers are being denigrated and devalued.

Like the postal service, public schools and the educators who work for them are an example of a government institution that is visible and works well, so to the conservatives destroying that is paramount to show that “government doesn’t work.”

And teachers are an easy target, as even in academia someone who “just” teaches is seen as far inferior to a researcher who also teaches (usually poorly) on the side.