Why is it suggested to "范畴论" translated with "general nonsense"?
https://en.m.wikipedia.org/wiki/Abstract_nonsense


  In mathematics, abstract nonsense, general abstract nonsense, and general nonsense are terms used by mathematicians to describe abstract methods related to category theory and homological algebra. More generally, “abstract nonsense” may refer to a proof that relies on category-theoretic methods, or even to the study of category theory itself.