regardless of what people's perception are, telling people how they can dress or not is wrong. In islam we have been told to pass on knowledge, not to enforce it on one. SO by havin these restrictions on non-muslims is not fair let alone muslims.
But they are still selling it to muslims so why dont they enforce rules on alchohol too. Anyways this topic is debatable, and one should have the choice of wearing what they want.

N.B: Most of the abayas are so fitted so it really defeats the purpose of Hijab. Wearing fitted clothes that shows ur figure is just as bad as wearing short skirts