> they often make blog posts in which they clarify how they want "proper french" to look like.

Anybody has the right to do that, they're mostly writers so they have an opinion on the language, but at the same time they're not linguists so they can't really be a prescriptive source. They just give their (usually reactionary) opinion.

I was just making clear that they don't make the rules. The Ministry of Education kinda does, and is often at odds with the Académie especially when it comes to the orthography reforms.