I agree with your skepticism, and I think it is healthy, but on the other hand what is being said in the post is sensible.

The best way to read this, or most of the internet really, in my opinion, is as if he were a friend, a colleague, family or an acquaintance, not as an authority; you listen politely, nod and smile, and reflect/research on your own on what it seems useful.

At the end of the day, the web enabled anyone to write, and this guy should not self censor just because that advice could be given elsewhere by a more authoritative role. It is his personal blog that we are visiting! If you were talking to a friend over coffee/beer about an idea that seems important to you that he hears, wouldn’t you be energetic, perhaps taking an “authoritative” tone? Not far-fetched!