ROB, I never said it is. However, it is provocative enough for it to be ossur. That is the accepted psak. I guess the Poskim hold it is part of the shok. Plus, there has to be a boundary some place — “ad kan”. If the lax among the women were allowed not to cover the knee, they would start wearing skirts 3-4 inches above the knee. And that would be only a start — eventually it would go higher. Or according to you, as long as they are not wearing bikinis in public it’s ok. Like I said look up the sugya in Sotah 3A with Rashi.
Plus, about the hair. It is different from the other ervas. Note, single girls don’t have to cover it. It has to be covered because of the Halochah that an eshes ish has to cover her hair and not because it is so provocative in and by itself. I expect you to agree that a lady wearing only not see-through tights without a skirt looks provocative.