In my personal opinion, the fact that in discussions about 10x engineers, many of the anecdotes and ideas try hard to discredit/disprove the concept¹ rather than presenting real-world examples of very productive engineers, indicates the fundamental will not to
recognize them, simply because of pride.
So I'll give a short and sweet argument: read John Carmack's biography and code (both in detail), then feel free to argue that he's not a 1000x engineer, and/or that he's the only one in the engineering world with such capacity.
¹: I agree, though, that "10x" is a profoundly misguided label