Everyone is part of a "circle of life" if you will. It doesn't matter if a person works at McDonalds or is nuclear engineer, they are all important in some fashion.
Back to the teacher and doctor discussion I would like that add that they are equally important. Teachers teach the doctors how to be doctors. Doctors treat teachers when they are sick which allows them to continue teaching.
Society is functional in a very intricate way. Everyone has a role to play whether it be the stay at home mom, the teacher, or the doctor.