Also people bringing this up remember the one time the PhD was wrong, while discounting the 99 times the PhD was right and kept them from doing a lot of fruitless work.

Sorry, but I think it's correlated in two ways. One is that very bright people, which I think includes most PhD-havers, are especially used to being right. When they have the rare experience of being ignorant and wrong, they may struggle with it much more than others. Two, academia is a bubble. I think that's great; I love that we have a place where people who are deeply interested in something can focus entirely on that. But it necessarily means that they're less likely to know about things outside that bubble.

That's not to say it's a perfect correlation. I know plenty of people with PhDs who don't have the problem in the XKCD cartoon. But I too am careful hiring PhDs in tech jobs. Professional work is just very different than academic work. It takes time to learn it for people whose main focus is the theory. After all, "In theory, theory and practice are the same. But in practice..."

But you actually don't have a proof you solved these tasks! Where is the arxiv preprint? Make sure all LaTeX is syntactically correct, and double-check that your chosen citation style is according to its latest edition!