"Yet research shows that most women who wear the niqab in Canada arrive at the choice themselves – as an expression of their Muslim identity,"
Wearing niqab correlates perfectly with islam. there is not ONE woman or man who "freely" wears a niqab. It is prescribed, or at the very least the women feel it is their duty. But for Islam, we would never see a niqab on any woman or man.
Lynda Clarke is disillusioned if she thinks muslim women are "not following any authority".  These muslim women are following the authority of the misogynist myth they believe in. 
The niqab is anti-social by design, so it is not surprising that people respond accordingly and want nothing to with them. What is surprising is that niqabbers cry islamaphobia when others do exactly what the muslim women want them to do - ignore them.