"Forget First Drafts; Write Perfect the First Time Instead" or "Forget The Way That Happens To Work For You; Write The Way You Failed To Do For Years Instead".

Blog posts are probably more readable than Twitter threads; I won't argue that. But if using Twitter is the thing that gets you to get ideas out of your head and into the written word, it's a hell of a lot better than just thinking about that awesome blog post and then never writing it—and, as siblings have noted, the "dump into Twitter, revise into a blog post" flow is both common and totally reasonable.