This is where ulema differ. For someone that wears niqab, it is in fact compulsory and we should respect that.
Like @Captain_Obvious pointed out, the perception ( and/or persecution ) of muslims is out of ignorance and xenophobia. If we simply change our ways, we are not adding any value to this society and we are missing out on an opportunity to educate them. Not because they are ‘backward’, but because we want to leave a better society for our kids.
Frankly, I’d be more wary of muslims who go ‘underground’ when they encounter such bigotry, rather than challenge it lawfully. Those are the ones that are capable of real damage to the muslims in the west.