I like your analysis. It makes sense and explains several unusual things I've noticed about these people. Thanks.
Another group is the agnostics. My Dad was one. He had no hatred for religion. (My mom was born-again). He would go to the church occasionally and help various members fix their stuff. But he had absolutely no interest or curiosity in religion. I once asked him if he had ever thought about life on other planets. He said "no". No curiosity whatsoever about anything that wasn't a material object he could see. He certainly wouldn't have been bothered arguing ad nauseum about it.
I like your father already.