If baring shoulders isn't associated with being glamorous, sexually attractive and overt femininity, why are so many wedding dresses and ballgowns strapless and Bardot tops named after an impossibly gorgeous and alluring woman?
I lost out on a job because I was wearing a high necked halter top underneath a suit jacket - it was around 95 degrees in the unventilated office they chose to hold the interview and they told me to take the jacket off before I passed out. Yes, their loss, but I was daft in wearing it in the first place.
My job requires that shoulders are covered as part of the workwear standards - I can wear a sleeveless shirt in the office on condition that I put on a jacket for meeting members of the public.
Most sleeveless tops I've ever looked at have armholes that are so low, there's always a fair amount of bra, if not sideboob visible. NOBODY needs (or particularly wants, to be fair) to see my bra, part of my breast or underarm hair at work. Admittedly, my price range isn't one where finding one made out of high quality material and perfectly cut to fit the proportions of each individual size is likely, but being in the Primark price range is exactly where the average teenager is as well.
If I'm treating a grazed knee or twisted ankle on a teenager, my focus in on the knee or ankle in question. However, whilst doing that, due to the compulsive shortening of skirts, I've also inadvertently seen way more than I ever want to see of teenage girls as, whilst they think it's marvellous that they have legs and can look just like their mates, they forget that not everybody is always looking from the angle where they think their buttocks, inner thighs and crotch are covered.
In a similar way, I've seen way too much of teenaged boy's bodies when there hasn't been an effective dress code - a vest top is usually so low cut around the arms that the chest is largely exposed, trousers so low that you see the start of their pubic hair, backsides (in boxers) hanging out the back.
I'm not getting off on seeing these parts at all, obviously - but I do think that it's inappropriate for me to see them.
If I were to have as much out as either group did, it would be seen as creepy and inappropriate around them - I'm sure quite a few of us remember having a teacher who wore low cut tops and leaned over in class (some more fondly remembering it than others) or who wore a short skirt and then sat with their legs up, either mesmerising or revolting the students with the full frontal Sharon Stone.
Anyhow, the unwillingness to even put on a short sleeved top or a skirt longer than four inches below gusset line is exactly why schools have begun to introduce 6th form uniforms and enforce them.