Trump made masks political, so wearing one is a political statement to these people.
They have made their political beliefs their entire personality to compensate for their low self confidence and so have to aggressively display their beliefs like a peacock anytime they think somebody is challenging those beliefs, regardless of how benign or irrelevant it is.
Aye, as an American, I have only a limited view of the big picture, but my understanding of it is that while it was definitely a politicized issue across the globe, a lot of the far right extremists were emboldened to make it such a big issue by the actions of Trump and the Republican party in the US.
Like that convoy of Canadian Trump rioters who can’t even vote for him if they wanted to because they live in Canada. Trump’s been a poster-boy for crazies all across the globe.