Is it normal to feel disappointed that the smartest people you know believe in a god or call themselves spiritual?

I've been finding myself disappointed lately that the smartest people I know in their field swear by things that can't be even be remotely proven to be true. For example. They call themselves spiritual and base their political ideas on that identity.

I'm not sure if I should look at them as an idiot from now on as I used to be the same. I know where they're coming from. It just feels weird that they can be so smart, an expert in their field even but fall so short in this lack of awareness. Like how is this even possible?

Could it just be me?

Is this an example of cognitive dissonance?

Is this feeling normal for anyone else sometimes?