Well, let's look at the situation closely. In this day and age children, in general, have no respect for their elders or those put in charge. They do what they want, when they want to. They are taught this at home as there are no consequences to their actions. Parents not following through with directions and discipline, giving meaningless "time outs" when a damn good tanning of the hide would be in order. I'm not talking abuse here, I'm talking about the need for a firm hand and firm heart (they must go together) in the child's upbringing. Liberalism has destroyed that like it has most fabrics of our society. How many of these children actually have both parents living at home giving them a balanced upbringing from a woman's and a man's perspective, working as a team?
If I was in charge of those children I close all curtains and lock them inside, as I would have very little confidence they would follow my instructions if they were outside. Not to mention my legal culpability, if God forbid one or more gets injured or blinded. The children lose in this one, because their elders have let them down and not taught them proper discipline and respect, not because the teachers are snowflakes.
Not very often I side with public school system on anything, but they are making the right choice here given the circumstances and potential pitfalls. It is all a testimony to our current lot in life living under the liberal jack boot.