It doesn't mean they are bad people or not smart or talented in other ways. This was driven home to me, well, it isn't recent any more, but the woman who directs a gospel choir I am part of is a flat-earther. I was with her on this in the beginning when she was first getting into it. She Facebook DMed me about it and I gave her factual references and what I thought were good arguments, but it was clear she wanted to believe. She is an utterly brilliant musician, as well as a good, kind, and fun person. She never breathes a word of it during rehearsals, for which I am grateful. There are other flat earthers and anti-vaxers in this choir and I'm pretty sure who they are, but we all love making music together. It is as if everyone is aware of these differences but we all love the choir so it's like there being those topics you don't bring up at Thanksgiving.