There are lots reasons to wear the Hijab most is a sign of chastity, its a sign of a rightous women who believes in God and covers herself. See the pictures of Mary (upon her peace) in the link below.
Do you remember the clothing of Nuns? See second link.
This is the same for Muslims women.
Remember that true beauty is not the skin, true beauty is whats in the heart. Beauty as they say is skin deep.
They have forgotten about Nuns, they cover up out of fear of God, why shouldn't others?
This goes back to the new testament where one of the strongest commands, is for a praying woman to cover her head. This is where the background comes from, I have added some interesting quotes.
Corinthians 11.6 "but every woman that prayeth or prophesieth with her head uncovered dishonoureth her head."
The Muslim woman who is covered for the sake of God is amongst the best dressed women on the planet!
While those who show themselves in various states, do it be attractive to men.
Its obvious which one is better.
Muslim women should also remember that whist they are wearing Hijab on, they are in a state of worship and will be rewarded for such. More than men in this case.