I'll admit that I'm apparently a dumb American, because till now I thought those women were forced to wear those black robes that cover everything but their eyes. They really like it, and they aren't coerced with any kind of religious pressure?
For example middle east people believe that women should not display themselves in public, on the other hand they DO should display themselves at home for their husbands, this led to some curious architecture, where homes have one "public" area, where visitors are welcome, and women show up covered, and a "private" area, that depending on the home not even male adult sons of the family is allowed, where women can stroll naked or almost naked. (this when dialed up to eleven that results into the "Harem" that for necessity reasons need male people working on it, thus the eunuchs)
In Egypt the reason for why a women should cover herself still apply: people (specially desert semi-nomads) still kidnap beautiful women. Since covered women you do not know if they are beautiful or not, they don't kidnap them.
Arabs are specially wary of Tuaregs, Arabs perceive them as women kidnappers, and I think that perception is not all illusion.