Educational philosophies are often a cause for heated debate. My children were enrolled in an alternative school for some time. I took an active role at the school, first as a parent with voting rights in important decisions at the school, and later as a volunteer. The volunteer work transitioned into an elected position as a staff member. Our school was modeled on the Sudbury Valley School. The main aspects of these schools are full democracy and complete academic freedom. The school was very up front about its core philosophies.
One thing that happened repeatedly at this school was that during interviews with parents prior to their children enrolling, they did not come to a full understanding of the philosophy. They would take issue with the degree of freedom that their child was provided with weeks or months after they entered the school. Some parents had practical or social reasons for placing their children in the school. In many parts of North America, governments do not legislate or enforce any type of standard of education in private schools. They consider the oversight to be the responsibility of parents. I don’t think all parents even understood that.
While looking on the Internet for controversies related to alternative schools, Waldorf schools have risen to the top. The main thing that critics point to is the deceptiveness with regard to the underlying beliefs and philosophies. The obvious reason for concealment is the fact that the founder Rudolf Steiner had views that are understandably repulsive to modern parents. Modern parents are the main source of income for Waldorf schools. Personally, I would never consider such a school for my children. Any organization that develops a culture of concealment is no place for children.
Realistically, parents have to face the fact that every teacher in every school, public or private, has a set of beliefs.