You should have the education required to both define the word 'rude', and use it with nuance. It's a bad look for an educator to use semantics to weasel out of their responsibilities.

Keeping your mouth shut regarding your opinion about the rationale for a specific tardy instance, costs you zero minutes, and allows you to go back to your resource management game, earlier.

Without a single repercussion to your process, because as you already previously mentioned, it is simple too much to expect of you to address any of them until the consequences of serial tardiness/truancy come into effect.

Your children must be respectful to you. They have not yet signed the social contract.

I owe you no such thing and am already being exceedingly more cordial than I believe your blasé approach towards your effect upon the psyche of your wards merits.