girls who so far wore headscarves had to enter their classroom one day, shamefaced to a jeering crowd who enjoy her humiliation...

I'm not going to suppose that this never happened, but do you have any evidence that it did?

My impression of French schoolkids at least is that they are generally prompt to take the side of the victim (as in immigrants and asylum-seekers that are under expulsion orders). Isn't "jeering crowd" a fair amount of projection?