Maybe they would act better in school if they did. From what my parents told me, when they were in school girls were required to wear skirts below the knee and boys couldn't wear jeans. The worst discipline problems they had in school were children chewing gum and talking out of turn.
Now that the lowest common denominator is celebrated in our culture, we have teachers getting beat up in class and shootings in the halls. Sometimes, change is not for the better.
When I was in high school girls wore blouses/sweaters and skirts/jumpers or dresses.
In neither era,were dungarees allowed to be worn in ANY school...from grammar through college and girls were NOT allowed to wear pants.
My daughter NEVER was allowed to wear jeans to school. She went to schools that had dress codes.
The worse one is dressed,the worse one behaves. The more formally one is dressed,the more formally one behaves.
And yes, back in the '50s,the worst problems most schools (though there were exceptions,where kids did carry knives and guns to school!)faced with students,was gum chewing and talking in class.