In Scott's mind, dangers from AI are not a known fact, but are somewhere between highly probable and a near-certainty. In his mind, there are well-grounded justifications for believing that AI poses substantial future dangers to the public. Therefore he also believes he should inform people about this, and strives to convince skeptics, so that we might steer clear.
It's easy to understand why someone who believes what you believe about AI would of course not warn people about AI. It's also easy to understand why someone who believes what Scott believes about AI would want to warn people about AI. Your contention is with his confidence for being worried about AI, not his reason for wanting to warn people.
Neither can any specific discussion of what the dangers are and how we can steer clear. It all comes preplanted in your head. The only thing that Scott is playing on (as far as we can see) is your ingrained fear, by using an ominous headline, and a vague reference to something "scary" in the conclusion.
Of course there was no reason to "warn" you, you already believed in the scary future. Scott is just giving you fuel, which you seem to appreciate.
If only there were a way to see more of Scott's thoughts on the subject of AI..