This seems to be the theory of multiple intelligences + g-factor denialism + credentialism taken to an absurd extreme. I see this idea used so often in arguments, I think it ought to be a formal fallacy. I'll call it Silo Fallacy for now. The idea that Einstein was as capable of making an argument outside his lane as the person on the street is ridiculous enough, but Chomsky identifies as a "public intellectual" - that is his lane.
I'm not very proficient with the "theories" you've mentioned. I'm more into facts. The quote is not offensive and is not about Chomsky. Personally, I find it empirically true. YMMV