You're both completely right, and completely wrong. You're completely right that French is far from the only language with a centralized linguistic authority.

You're both completely right, and completely wrong. You're completely right that French is far from the only language with a centralized linguistic authority. (https://en.wikipedia.org/wiki/List_of_language_regulators https://en.wikipedia.org/wiki/List_of_language_regulators) As a matter of fact, the United States is all in as a language regulator: they have a language regulator ... for Spanish! (https://en.wikipedia.org/wiki/North_American_Academy_of_the_Spanish_Language https://en.wikipedia.org/wiki/North_American_Academy_of_the_...) Where you are absurdly wrong, is where you say that the threat to a language is the reason for the existence of a language academy. It simply isn't; the reasons are purely historical for almost all languages. I mean, Cardinal Richelieu founded l'académie française. French was not threatened during the reign of Louis XIII!