I’m not sure if what I am about to say is implied in any previous comments, but here goes.
The issue I have with the burqua women is simple. I strongly suspect that the burqua is not a mode of tznius. I postulate that it is a statement of arrogance, “I’m holier than thou.” As such, it does not truly represent the positive, but rather the negative. To exploit the midah of tznius in a negative manner is unacceptable.
Perhaps, when dressing in this manner was the norm, there was no haughtiness to it, and it can more easily be an expression of tznius.
Additionally, I have no issue with women covering themselves up more. But when doing so actually triggers more to focus on them, the values of tznius are being undermined. I am not even blaming this on anyone, just looking for the norms and patterns.