To my knowledge, that sentiment stems from distrust of authority and an abhorrence to coercion. I don't think coercion is the right term here.
If you're not vaxxed or wearing a mask then you're not allowed in those places is reasonable in my eyes.
I can understand it but I don't sympathize nor truly comprehend the principles.
I've been wanting to so that I'd be part of the "cool" kids and that's a fact. It's always been about me and how I want to feel like I belong to a group.
I've my fair shares of anti-mask and anti-vaxx sentiments but the degree to which many Americans take it is beyond me.
Maybe I will never truly understand it and maybe I should accept that. I just don't like not understanding. It makes me feel unprepared.