You have clearly not encountered theoretical computer scientists. They love to create all kinds of complexity classes and theorems to capture things like heuristics and approximation algorithms and other things which work in practice but not theory.
In fact that’s a big research thrust right now, to understand why many real-world SAT instances are solvable quickly while others are not, and where the threshold between them lies
I studied mathematics, and can attest that the attitude of the professor mentioned in the article is very representative of an older generation of mathematicians. Maybe the younger ones are different.