People's ideas don't form in a relativistic vacuum. If someone's opinion is that only 50 million people voted for Biden (because they've been watching too much My Pillow, perhaps), that's a false idea resting on provable lies. If that opinion leads them to treason and to jail, that's a problem for all of us.
If their opinion is that Trump is much better looking than Biden, that's an opinion on a matter of taste and I'm fine with it, as I am with their opinion that my mask looks stupid. But they don't get to come into my work without a mask and put me, my coworkers and the people we serve at risk based on an opinion.