How far are you willing to take your argument? 
A democracy is a place where the majority rules. No? So if 7 out of 10 Canadians and 87% of Quebeckers object to face covering garments worn by even a few women do we then not have a good argument to ban such garments?  
Not because we don't like the fashion aspect of them, but because this majority argues that the niqab is an expression of oppression and backwardness in our open society.  Today there are few in Canada, but taking Europe as an example where many city suburbs look more like Kabul than Paris, Brussels or Rotterdam we should be careful.  I'm old enough to remember when  women had to wear a hat to church and a black veil after family deaths and I for one don't want any of even that back.  
What is often ignored, and what to me is repulsive, is seeing some muslim families out for a walk with dad and sons ahead sporting their latest  shorts, Ts and sneakers while mom and daughters trail behind in head covering long garbs.