This is a non-sequitur in context: Gwern's whole thing is trying to take a from-scratch look at the literature instead of relying on the standard appeal-to-authority arguments that sometimes lead to flawed conclusions due to things like institutional incentive structures. That is to say, if you're the kind of person who reads thing blindly based on whether the author is an expert or not instead of taking advantage of the fact that he shows his work to assess the quality of his analysis, then gwern's writings probably aren't for you. (FWIW, you should probably be doing this to some degree even when reading the recommendations of those designated experts)

Don't get me wrong, there's obvious ways for "ignore the experts and read the literature from scratch" to lead to flawed conclusions, but it's just a different type of analysis.