I don't think they are trying to impress each other, or are contrarian for the sake of it. I think it's a fair amount of legitimately smart people who don't have much in the way of life experience, may be in part on the autism spectrum, and tend to be engineer/rational types who think systematically more than intuitively. I mean they construct and deal with systems.

This leads to sort of a naivety that tends to look for elegant explanations of a sort and is vulnerable to them. The all-explaining system of thought that in general intellectuals tend to get ensnared by, but is self-contained and self-perpetuating. The idea of the messiness or stickiness or even corrosiveness of life on these systems tends to not be entertained much, as it reduces the power of rationality.

So the rationalists get really vulnerable to these kind of left-field ideas like AI risk, or neo-reaction. These ideas are often rationally elegant in the way many negative systems are; they are a novel way of explaining things. The red pill/manosphere stuff was similar; as a system of thought it's a lot more elegant and explanatory to its audience than the alternatives, and even criticized actual things as well as its own untrue things.

I guess I'm saying is that it's more the rationalists are vulnerable to getting captured by those contrarian ideas you describe than they are malicious or doing it to flex. It's not really unique to them, academia goes through it, philosophers go through it, artists go through it, etc.

As for the cultish stuff, its apparent to me that a lot of rationalists are kind of adrift in real life due to the great unpersoning of religion and its replacement with woke or trumpian politics. Thats part of why the grey tribe was coined, neither left nor right. They need meaning as well as anyone.