Since Yegge provides no evidence, and a lot of criticism of the current culture of Clojure, I must assume he is relying on his authority to make his case. There's nothing else to back up any of his assertions. It's either argument from authority, or argument for the sake of argument with no rhyme or reason at all. While argument from authority is weak, it'll convince a few people who think he has authority to speak on the subject.
But, his arguments are clearly not technical. He makes no case for why those languishing patches deserve to be in Clojure...just that they exist, and that's enough for him to believe they have merit.
"As an aside, Yegge has achieved something noteworthy in language marketing: his writings about programming languages have a large following. Perhaps he exaggerates his influence, but for better or worse it's non-negligible."
I don't disagree. I enjoyed Yegge's blog immensely over the years. But, talking loud on a blog, and building a language community aren't necessarily the same skills. I see people suggesting he had some hand in Python's rise to it's current position of importance, but I was a Python developer before Yegge started talking about it, on a major Open Source project...Python was doing just fine. It was actually entirely news to me that Yegge had anything to do with the Python community, in fact (it's been a few years since I was working in Python, so I haven't followed it since). Python made Python popular, not Yegge.