Teachers don't just teach and schools don't just provide academic training for our children. We send them to school to be taught and to be looked after so that we don't have to teach them or babysit them all day. To be fair to parents, there are many things we can't teach them, either because we lack the knowledge or are devoid of the necessary skills and temperament to teach effectively. We love our children but do we really want to spend all day with them, every day? We've got our own interests and pursuits: work or leisure. So we need free babysitting, and as a bonus, our children actually learn a huge amount about a whole lot of stuff.
They not only gain knowledge and skills but also values, and it is this last area of acquisition which is by far the most important. Those universally accepted values which we are required to not only know but to practice, and which transform us into loving, caring and respectful citizens, are either taught or reinforced at school. Do we want teachers imparting values to our children? Do we trust them? Do we even care? As long as they are being babysat, as long as they are safe and happy, does it really matter what else happens at school? What is a parent? What is a teacher?