Neko-Ali, as someone who grew up in a non-fundamentalist household that regularly attends a fairly hardcore fundamental southern Baptist church, I kinda resent you calling fundamentalism a cult.
That said, there's definitely cult-like elements in how certain people adopt the religion. My parents both have rigorous science backgrounds and taught me critical thinking from a young age, and I think that's a part of why we've never quite fit in perfectly at our church. It doesn't leave us marked as horrible, unworthy sinners, it just makes us strange and creates awkward gaps in conversations where we're silent as people wait for us to agree with them.
I absolutely agree with your analysis of why he talks the way he does; I've seen it in my own life. Hell, when I was little, I definitely sounded something like that concerning certain topics. People do it, but it's definitely a trait developed by individuals, not entire churches universally.