When there is extreme on one side, it causes extreme on the other side. When girls are taught in BY schools that their worth is dependent on how unattractive they make themselves, and there are teachers who walk around with rulers and measure girls skirts, it causes many to rebell and to hate the idea of tznius.
When girls see teachers who are dressed with complete lack of personality and color, all black and same stiff wigs, it really backfires on many girls.
