Indeed parents have a duty to their children. Clearly this cannot and should not mean that they're allowed to treat their children however they want or that they're allowed to educate them on what and how they want. There can be a space for them to make decisions but the rights of the children always have to take precedence.

It's only natural for the government to step in and determine exactly what this means. Allowing the government to do this without limits is problematic, so you balance that out with rights assigned to parents.

It's not an easy question to determine where the line should be drawn but I don't think it's really all that totalitarian to prohibit home schooling. It ensures that children are educated, that they socialize with other children, get confronted with different points of view and gives them the freedom and ability to safely explore the world and themselves in an environment where there parents have much less influence over their lives. It should not be forgotten that not all parents are included to provide that without force.