The author’s critical approach to what is ‘polite’ is all well and good, but I have reservations about what she considers the limit.

As for the ‘doing no harm to others’, she must recognize that the harm her children do may not be readily apparent. When I’ve got a massive migrane, I don’t want to hear her kids screaming in the next booth over, but I also don’t want to have to confront her about it and risk her screaming also. Better to sit and suffer until I can’t.