Why do Muslim women wear the HIJAB?

They say that women have to wear the HIJAB because when they wear it men cannot judge them by their appearance, personality, character and morals.
To wear the HIJAB is not a responsibiliy is a right given by the creator that knows them best.
Women they only cover themselves in front of men.
Some women don't like to cover themselves because they not agree with it but if they don't do it they get punished so they don't have another option that obey to wear the HIJAB.
Some women when they are in there house they don't wear the HIJAB because they think that noone is looking at them so they do it but for their religion that is something that is not right to do because they have to wear the HIJAB always!!!!
http://www.islamfortoday.com/hijabcanada4.htm