The social aspect of schooling is just as important as the educational part of it. There's a reason growing up when we had home schooled kids that joined for their high school years, they were the "weird kids" - they just had absolutely no idea how to interact socially with their peers. And for some folks that carries on to adulthood.
Disclaimer: my parents were public school teachers, and seeing the system deteriorate feels like a travesty. The number of parents who think school is daycare is disheartening to say the least.