The law being discussed is for minors. As a society we don't think minors have sufficient executive function to make those decisions, so we find it acceptable to ban them in those context.
Alternatively: As a society we don't think ALL minors have sufficient executive function to make those decisions, so we let parents who do make that decision.
Alternatively: As a society we don't think ALL minors have sufficient executive function to make those decisions, so we let parents who do make that decision.