Actually true modesty is a woman doing it on her own volition.
The Muslim practice of the Hijab actually has partial roots in Byzantium. But of course, this isn't ancient Byzantium, and that was a cultural thing rather than religious. Seems modesty went out with Byzantium as well.
Modesty isn't asking women to constantly have their heads covered, or asking women to cover most of their body.
You have a really weird idea of modesty, or at least an idea that seems incredibly misogynistic.
To me, if a girl wears shorts slightly above her knee rather than shorts up almost to her crotch, she is being modest. The other day there was a girl in Chipotle who basically had those obscenely short shorts and they were kind of a similar appearance as Michael Jackson's glove. It even caught the attention of the older women in the store. I would consider that obscene. However, if a girl were to wear knee-high shorts, she is being modest.
I would like to see more girls wear skirts, not because I have some screwed-up view of modesty, but because I think they are actually more attractive and beautiful that way.
There was a time, not too long ago, when girls weren't allowed to wear pants because they were seen as too "sexy" and obscene, even though they showed no skin and men were allowed to wear pants. In fact, there was even a time when pants were considered barbaric and obscene.
If we stuck with antiquated ideas of modesty, we'd all look like the Amish.