People protect the idea of the school teacher like it's part of the foundation of the thirteen colonies, inherent in the core of our American being. But it's not. It's actually the result of the destruction of family. Starting only with the industrial revolution, while the rich people who needed factory workers were advocating that we put kids in school all day under the premise that the parents were incompetent.
Check out this excerpt from a 1906 document by John Rockefeller's General Education Board, the group that originally decided what public schools ought to accomplish (via Jay Cross, king of do-it-yourself college)
In our dreams…people yield themselves with perfect docility to our molding hands. The present educational conventions [of intellectual and moral education] fade from our minds, and unhampered by tradition, we work our own good will upon a grateful and responsive folk. We shall not try to make these people or any of their children into philosophers or men of learning or men of science. We have not to raise up from among them authors, educators, poets or men of letters. We shall not search for embryo great artists, painters, musicians, nor lawyers, doctors, preachers, politicians, statesmen – of whom we have an ample supply. The task we set before ourselves is very simple…we will organize children…and teach them to do in a perfect way the things their fathers and mothers are doing in an imperfect way.
So school is there for kids who have incompetent parents.
Teachers today echo that sentiment. When you ask them why they continue to work in such a messed-up system, so many teachers say they do it for the kids. "We have to fight for the kids!" As if that is not the parent's job. Surely parents are way more equipped than teachers to fight for their own kids, and teachers can and should get on with their lives doing something that does not assume parental incompetence.
There is a snowball effect for teachers who are looking for a way to justify their continued participation in a system that largely devalues them.
For example, I saw this quote over a teacher's desk: "Teachers who love to teach teach children to love learning." The quote assumes that kids are not born loving to learn. It's a sad assumption. It assumes humans are not innately curious, which we know from the history of everything before the industrial revolution to be untrue. The aphorism also assumes that kids, left to their own devices, will stare at the wall all day instead of learning through play. Which is another thing we know to be totally untrue.
So teachers have to convince themselves that both kids and parents are largely incompetent at being their natural, curious and caring selves. This is sad because it is so obviously wrong, but it makes sense. Because people who feel confident, capable, and important do not continue working within an organization that everyone agrees is a total failure.