DaMoshe,
I also doubt that tzius was taught/enforced the way it is today.
In my mind, there is a sharp distinction between a school environment and the rest of the world. Everything that you are describing below is apparently happening within a school environment, and it is not unique to Jewish schools, but any school with uniforms or a dress code policy (which includes public schools). Perhaps the only unique aspect to it is that it is being labeled tznius.
There weren’t teachers with rulers measuring how far below the knee a girl’s skirt was reaching.
This was done in my public school when I was young. The standards weren’t the same, of course, but there was a code and it was enforced.
They probably didn’t have rules about how a girl should tie back her hair.
I’m sure many schools did. My public school certainly did for certain circumstances.
No rules on what color clothes girls should wear.
At the public school I attended, clothing with words or logos were not permitted. Other schools require uniforms. I don’t see why this is a knock.
The chumros just keep piling up, and it turns people off to the whole concept.
I don’t see these as chumros, just school standards. Perhaps the schools should describe their standards as relating to the school environment itself (e.g., this is what we require girls who attend our school to wear, and by the way it is a good example of dressing b’tznius).