Hijab is being said to be for good of women, to protect them. Even if it is true and is really for good of women, you're still never going to make anyone do something which is supposedly good for him/herself. Muslims are smoking but no one cares if it is good for them or not.
Having hijab is a must for women in Iran. It is a law. Even though I don't like it and I would have taken it off if I had been allowed to I have never had a problem with having it because it was always a part of my costume since I was nine. When I was a believer, I used to practice my religion precisely, step by step but even at that time I had a hard time understanding the purpose of having hijab. Women have to cover their bodies (minus their faces and their hands up to their wrists) when they are doing their prayers even when there is no man at the place. Rami could confirm how much we discussed it when he was a regular member here