Nope. Dress codes aren't "new" at all. When I was in grade school (admittedly in the dark ages...LOL), girls HAD to wear a dress to school. No pants permitted. This was in Minnesota. And, included the winter time. In the winter, we wore pants under our dress until we got to school, and then we had to take the pants off. SMH. My parents wouldn't dream of questioning the dress code. They complied. Easy.
I have ZERO problems with reasonable dress codes. The only reason they are necessary is because there ARE trashy parents out there who think it's fine to have their "snowflake" where a t-shirt with swear words on them, or shorts that have their **** hanging out. Dress appropriately for school and there's no problem.
My D does have some issues with the "fingertip" rule for dresses. She is quite tall, and dresses simply aren't sized for girls who have as much leg as her. Still, she CAN find things that are appropriate, and the other dresses can be worn other places. (BTW, she always wears bootie shorts under her dress, which seems to be the custom at least in her school).