"In fact, the opposite is true. In every western nation where there are large concentrations of Muslims, there is agitation for implementation of Muslim laws and practices."

And this is exactly the claim that the article is trying to counter, because it's untrue.  The people agitating are those trying to gain support for their cause by preying on your fear of brown people and OMG Sharia!  Their cause is white nationalism, and the more people they can scare with OMG Sharia!, the better they like it.  

Rather than just believing this stuff, we need to ask, "Who benefits from promoting the idea that Muslims are seeking to impose laws and practices on us?"