Because the output contains evidence of thought processes that have been established as leading to valid solutions to problems.
I have a simple question: Is text a sufficient medium to render a conclusion of reasoning? It can't be sufficient for humans and insufficient for computers - such a position is indefensible.
I didn't mean the wording itself; I meant that the claim isn't convincing to me for the same reason that Lucky's speech doesn't demonstrate an intelligent speaker.
I would say that almost all of what humans do is not the result of reasoning, and that reasoning is an unnatural and learned skill for humans, and most humans aren't good at even very basic reasoning.