But it is a simple fact of life that not everyone will agree on everything. Would be nice to stop having crimes so that we could divert resources away from fighting criminals and into more interesting endeavors. Doesn't mean that this will happen. Ever.
I try to do what I believe is right, which is to put myself in other's shoes. Others will simply take your shoes because they like them more than their own, and they can justify their decision to themselves as perfectly as I can justify mine.
And so some parties and their voter base like to build their beliefs and policies on a scientific basis. Others prefer what has been done before, what god said in the bible, what their gut feeling says... Whatever. It is a simple fact of life that people do things differently.
The fundamental issue is that, in a more and more globalized and interconnected world, we have to force people to do what's "right", whatever the zeitgeist believes is "right" in that moment, because all of society hinges on it.
A thousand years ago, if the villagers on the other side of the river decided to start eating poop and all caught some form of deadly illness, it was their issue. Today, the entire world ground to a halt because somebody in china coughed too much in somebody else's soup.
It's an issue with democracy and modern society, really. That every voice counts, especially the loudest, and that every voice must work with all the others, or else the whole thing comes crumbling down.
So yeah, it's not that being pro or against vaccines is stupid. It's that our lives are in the hands of everyone else, and that someone being stupid will ruin a civilization and put everyone at risk.