I think the focus on underwear being on show is over egged
The problem is male attitudes to women and victim blaming
Not the girls and not the skirts
It's not over egged at all. It's not unreasonable for everyone (male staff, female staff, male students, female students) to follow their respective dress codes. Rolling skirts so short that underwear is on show is not ok.
There's two different issues:
- Male violence, male perving - totally the responsibility of men, not girls, not skirts
- School uniform - it's there, there are the expectations, it's really not difficult or unreasonable to expect boys and girls to follow the uniform.
The wider feminist discussion is why girls are socialised in this way, and why is it so convenient that they grow up to feel that this is a good thing to do. It's a societal issue and they're not growing up in a vacuum.
The wider educational discussion is why some adults are weirdly invested in their children's right to ignore any part of the uniform to the point that they're willing to push for girls being able to wear any length skirt. Some parents are apparently incapable of following a uniform policy, even ones that are quite clear.
If my workplace says no jeans, then it's no jeans. It doesn't matter what DH's work does, or if my friend wears jeans, my workplace says no jeans. It doesn't mean there's anything wrong with jeans, they're just not in the dress code for me. Wearing jeans and then moaning if my manager spoke to me would be silly.
Same for school uniform. I've only worked in one school that has a serious problem with skirts. The rest didn't the same thing as when I was a teen, the students pushed it a little, nothing stupid, staff reminded, everyone got on. The school with the biggest problem on uniform had countless other battles with parents thinking school rules were a pick n mix option