I don't agree. The curfew has everything to do with deterring crime. The kids are in public places, hence an issue for governmental authority. Kids in public schools are subject to government authority while there. Kids being schooled at home are not in public places with the potential for crime and mayhem, so there is no basis for that level of control.
For the state to exert some control over when and where minors may gather/loiter/waste away in public is not a huge deal; they're still only affecting public places. (Although this does raise the question of how the state can dictate who may or may not gather/loiter on private (business) property away from their homes.) When the state intrudes into our homes to dictate what is taught there, we have one serious issue to combat.