Note that Julian runs an SEO and growth marketing company, so the type of writing here is more for that purpose, to sell your product, than to become the next great author.
Maybe he should have put that in the title then, rather than proclaiming to know how to write well in general. Such an imprecise title is indicative of a poor writer, so I guess there is a good amount of irony to be had. Who knows; maybe he's a brilliant satirical writer.
Considering he has others on "being rational" and "building muscle", I just thought he was one of those tech bros that loves Tim Ferriss and feels that same need to create prescriptive tutorials on topics they aren't domain experts in.