I never made the connection until reading your comment, but I now wonder if they heard about the incompleteness theorems and came to their conclusions about math based on a misunderstanding.

I’m sorry to hear that concept disappointed you, but I personally don’t think it ultimately matters or effects the usefulness of math. I see it as similar to the difference between science and engineering. An engineer can create something useful by knowing what works, without knowing precisely why it works. A scientist tries to uncover why things work the way they do, regardless of the utility of that understanding. Often the output of those two fields overlap, but they don’t have to.