I'm still confused what he's using this "skeptical of reason" statement for.

His core conclusion, which I agree with, is "true reason and rationality are very difficult." He then goes on to say that therefore "we need to be skeptical of reasoned arguments."

The best interpretation of this principle would be "just because something sounds correct to me, doesn't mean it is; be careful of clever arguers." That's worth a blog post, but not more than one, and the catchphrase "suspicion of reason" makes a worse interpretation plausible: that he's using it like "I think your argument is reasonable, therefore I don't have to listen to you or change my mind." But hopefully that's not happening.