I find this type of argument confusing. Let's say we did live in a world where their hypotheses were true. To make it concrete, let's say that a SuperAI was 20 years away and would wipe out humanity. How would we be able to know that right now, other than through the type of speculative inference you're criticizing?

Put another way, just because something is impossible to demonstrate conclusively and/or via observed reality does not automatically mean it can't be true, right? Of course it does mean that these claims warrant far more skepticism, and probably the large majority of them are untrue. But it seems obviously incorrect to automatically assume that they can not be true. Am I misunderstanding your reasoning in some way?