Pre-education is swinging too far in the opposite direction for your own argument. Jacobus Uys the guy who wrote The Gods Must Be Crazy was sixty when the film came out in 1980. He watched the entire shift from the machine age to the nuclear age to the information age. His required childhood education in the 1920s and 1930s would've been six to eight years with highschool as optional. His parents who were children in the 1890s likely would've had education be entirely optional. He lived through the change from school being a privilege to being required and watched as it grew from six to eight to twelve years. The film itself is literally about the dichotomy between a post-agrarian tribe and nuclear age civilians and how less than a century separated most of the world from being one before they became the other. He wasn't reaching back to some pre-modern past, he was commenting on the rapid expansive changes he had seen during his own lifetime.