Muslim women burka's?

I live in Canada and i often see muslim women in Burka's and other such things and although its your right to wear whatever you want and i would defend to the death your right to those freedoms i was just feel as though its a dis-service to the women in Muslim countries who dont have a choice and must wear them less they be punished (and quite servilely so i hear) You women are now in a country where you have the right to wear whatever you want, get an education, ect and you chose to promote a culture and religion that encourages the degradation of women. Im not saying to abandon your religion once you get to Canada (although would if it prevented me from learning to read) but why keep the burka now that you have choice.