This is the way it should be in schools in a free society. Education, like healthcare or clothing, or food, is a personal responsibility best filled by private industry. When the government owns the schools and forces people to patronize those schools freedom suffers. Of course, the question of posting the Ten Commandments is just the tip of the iceberg. Government control of the education industry causes far more problems than whether or not the Ten Commandments are suitable readings for children.
Most people recoil in horror when one suggests that.
Thinking people disdain the idea of some government worker educating their children. Unfortunately, that is the norm in our education industry. Teachers are government workers. They are therefore, by definition, bureaucrats. Parents who would never even consider taking their children to a government clinic for healthcare dump their children in government schools to be educated.