That should be brought up to the school board and parents should be up in arms about it. I don't see how it's even acceptable to require you to do paperwork every time you kid is late to school. If on the day I couldn't get a human at a school to talk to me and a phone call to the office didn't work either I absolutely would go home. People let others get away with this way too often. Sometimes you can't fight it (good luck fighting parking meters in your city that require an app once contracts are signed and the infrastructure is in place), but often you can demand reasonable accommodation if not a change of policy.