The kilts don't come short. They come at a length resting just below the knee.
Girls get their kilts hemmed and then roll up the waists to make them shorter.
I was guilty. It wasn't about being sexy for me, though. All the other girls did it, so I wanted to do it, too, so I could fit in. How it would affect males didn't even cross my mind, because everyone wore short skirts. I always wore shorts beneath my kilt but some girls definitely didn't. The older girls used to bully me in the halls because I wore shorts underneath and wore tank tops under low-cut tops. It was really overwhelming for a young teen.
My first Catholic school had strict uniform rules, and I got banned from wearing my kilt because I rolled it one day and the principal caught me. Pants only from then on. I was 14.
My second school didn't have uniforms when I began studying there, but they implemented uniforms in my second year. Students hated it, teachers didn't want to enforce uniform rules, so students got away with anything - wearing their own pants, wearing short kilts, their own sweaters over the uniform shirts, etc.
It wasn't until I was on a school trip to the threatre with another Catholic school that I realised the way I wore my kilt was very sexualised and portrayed me the wrong way. I was in the washroom at intermission, washing my hands, and these girls from another school were waiting behind me to use the sink.
"Don't you love it when sl*ts wear their kilts short? How cute, they're just dying for attention."
I told the girls to f off but from then on I stopped rolling my kilt up. I began paying attention to what my clothes were saying about me instead of just going with the flow and dressing like the other girls in my school. I never dressed horribly sexual, but I wore miniskirts/skorts and spaghetti strap tops and halter tops outside of school. I stopped that.
10 years later I only like skirts that fall below the knee and shirts that have no sleeves, but have thick straps (for the summer). No cleavage. I still wear really casual clothes but on the whole I dress better.