The churches for some reason I don't understand, do nothing to dissuade that belief even though no major church teaches it (nor ever has). Same as some people think the earth is flat right?

And no, I don't think anyone should be banned unless they break the law.

A single shred of doubt has a lot of power. As a comment above mentioned, ~38% of Christians believe in a young Earth. They are more than likely the ones who believe in the so-called "infallibility of Scripture". The percentage of the ~38% that might consider evidence brought to them by an authority they respect may also consider the fallibility of other parts of the Bible that those authorities endorse actively in comparison. That's my best guess at why church leaders don't ever talk about myths perpetuated by the congregation.

Damn that's a good point. I had forgotten about that "infallibility of scripture" belief. I think it's misguided and I generally avoid engaging deeply with anyone who holds to it, because to me any meaningful conversation is nuanced. That position is markedly not nuanced..