I honestly do not see a problem with this system. Kids need to be in school. Some won't. You have to have some way of forcing them to attend and be there on time.

You can lament and wax poetically about the unjustness of it all, but in the meantime we have kids to teach. And really, this isn't an unjust trap at all. You provide a mechanism to hold people accountable, and you give them enough grace to handle accidental twists of fate beyond their control.

I see nothing wrong with this system. You're dreaming of a utopia where every kid will willingly go to school and arrive perfectly on time, all of their own free will. You're lamenting that we don't live in a fairlyland fantasy world.