My impression is that he’s pretty controversial politically but that his contributions to linguistics/theory of grammars are generally seen as very impactful. And I imagine that in this case the reference is more related to the latter (?)
Curious to find out more about critiques on his work though (in all spheres)
One reason is that his fame among culture warriors on youtube is related to his third act (or arguably fourth). His first act in Linguistics, back in the 1950s, is relevant to Computer Science (eg: "Chomsky Normal Form")
As the author of the library, I'd like to note that I consider some of Chomsky's views to be... questionable. The choice of name was largely down to his work in the world of linguistics and parser theory.
anarchy and libertarian socialism is particularly popular among the American left. Though I think OP is from UK. Either way as a individualist and capitalist, I rolled my eyes.
Even among the right, I think anarchism and libertarian socialism are viewed more sympathetically than authoritarian leftist tendencies. Much like how the left is less vitriolic (in principle, at least) towards capitalist libertarians than they are to fascists.