I mean humans do that too, and I don't think it's very unjustified. The "we deduce from a deep base premise P down a chain of inferences" picture is extremely incomplete and has been challenged all over the place - by normal people, by analytic and continental philosophers, by science itself, etc.

Not trying to say that LLM's are equivalent to humans but that the concept of reasoning is undefined.

And the fact that their performance does increase when using test-time compute is empirical evidence that they're doing something that increases their performance on tasks that we consider would require reasoning. As to what that is, we don't know.