The author is consciously using exceptional with another accepted meaning of the word (rare). And you are (consciously or not) at the same time misunderstanding him and being condescending, while adding strictly nothing to the discussion.
This intentional use of the definition of a word from one context in another context is equivocation, a form of dishonesty that it makes little sense to tolerate.
I think this is exactly what the article author was pointing out, actually.