Would those who consider Chomsky an HP on linguistics care to say why?
The God of Linguistics is of course an FF for founding one of the fields I hold most dear to my heart.
Isn't the father of Linguistics one of the Grimm brothers?
It would be more accurate to say that he's the founder of contemporary linguistics and the person most central in contemporary disputes in the discipline.
Yep; that's why I used god and not father. Although linguistics certainly owes a lot to those who described the historical relationships between languages in the 1800s and early 1900s, the modern field does little in historical linguistics; we instead spend a lot more time
arguing about meaningless differences between tedious diagrams of syntax debating fundamental questions about what constitutes a language. Incidentally, Jakob Grimm did come up with
Grimm's law, they weren't the originators of historical linguistics... it was kind of a hobby for a lot of erudite romantics at the time.
William Jones could probably have a better case about being the originator of historical linguistics.
In any case, regardless of what one thinks of his theories, Chomsky's certainly the central player or at least the originator of one of the sides in the story in almost every academic dispute in linguistics today. Something like 20% of US tenure-track faculty in linguistics have gotten their PhDs from MIT, in large part due to his influence. His criticism of B. F. Skinner's ideas about language helped kickstart the
Cognitive Revolution that steamrolled behaviorism off the map (for a time, at least), thus almost completely reinventing psychology.