When I was a child I had long hair. VERY long hair. Like... Thigh Length. Whenever I felt like wearing my hair down no one ever complained or said anything of the sort.
I simply can't imagine any reason to do this to this girl.
All I can imagine is that the girl kept playing with her hair and that the teacher got so pissed about it that she thought she'd just "remove the distraction".
Maybe it was just my school. Like I said, I assumed it was required since nobody told me other schools don't do that. I was really confused when everyone in this thread was acting like having long hair down at school was no big deal. Now I know why.
I'm really sorry for my mistake!
I hate when teachers won't let you hold something in your hands while you work. I'm home educated now, and I find the only way I can think straight is if I'm fiddling with something. I honestly don't think I could concentrate without holding something.