I don't directly agree with the parent comment but I can see a productive argument that could be made against the current implementation of many school zones.

Mainly that if we want traffic to be slow and walking children to be safe, this can be accomplished by better planning and placement of schools and better design of our streets.

Slapping a blinking 30mph sign on a wide, straight, six-lane highway is kind of a brute force solution that relies on enforcement and compliance, and still leaves pedestrians vulnerable to a lot of car traffic. Anyone walking through or crossing the street during non-school-zone hours is also not afforded that extra level of safety.

Placing the schools on quieter streets with features designed to naturally slow traffic flow and promote safety for pedestrians and bicycles could accomplish most of the same safety goals and work passively 24/7.

As could designing neighborhoods so that more kids can walk and bike to school, reducing car traffic further during busy pickup/dropoff times.