“Even growing up, I knew I was one of the lucky homeschoolers. My family knew homeschooled children who worked in the family businesses instead of doing school, kids who could barely read and who had learning disabilities that their families were not equipped to even identify, let alone address. . . . In so many of these cases, the physical, educational, and emotional neglect was never confronted, not even by fellow homeschooling parents, the only people in a position to see it.”