As far as I can guess, it’s as if I’d asked, “On a scale where zero is ‘not difficult at all,’ how difficult does the AI problem feel to you?” If this were a bounded scale, every sane respondent would mark “extremely hard” at the right-hand end. Everything feels extremely hard when you don’t know how to do it. But instead there’s an unbounded scale with no standard modulus. So people just make up a number to represent “extremely difficult,” which may come out as 50, 100, or even 500. Then they tack “years” on the end, and that’s their futuristic prediction.
