I spoke to a guy I grew up with who's now an elder.
Even though he looked jumpy when I was saying some things about the Borg - he was at least listening (with a frown). Then he asked me what I thought of the bible.
I said I was an atheist... His whole face just went slack at the very word. Conversation over.
We continued to speak for a few moments, but his eyes were vacant. (It was actually quite creepy)
I think there is some truth to what you are saying. Some folks just will not listen to an atheist - the very mention of the word causes distrust and suspicion.