pioneer27, if it were a case that women were compelled to wear them, it would be a problem.  So far, there's no evidence of that in Canada.

(And by the way, that's not the definition of "indecent.")

Here's a Globe story about the woman involved in the citizenship oath case. The opposite about being "compelled": https://beta.theglobeandmail.com/news/national/woman-at-centre-of-niqab-debate-ready-to-take-oath-vote/article26716420/ 

What you didn't address is the Supreme Court decision that has already found a blanket ban on wearing a niqab in court is unconstitutional, in R. v. N.S.