I don't quite get the argument. So, the author likes XP. And possibly Rich Hickey doesn't as much? Did I miss a link to an article or discussion about this, or is this a general "touchy-feely" position?

"The dodgy attitudes come from the Clojure core, especially Rich Hickey himself, I’m sad to say."

where the "dodgy attitude" == "Rick Hickey doesn't believe that TDD is the only way to make software"