The post isn't about Clojure or Lisp, it's about the author's journey as a programmer, and the mind-bending effect learning a Lisp had on their development. They're still in the midst of figuring it out, but a lot of people have been on this path before them. TFA has been written over the years by various authors about Prolog, or Haskell, or Smalltalk. In my case I would have written it about Lucid.
The interesting bit here isn't related to Clojure or Lisp, that's what people are chewing on because it's the surface level topic of the essay. The thing that interests me about this post is how it touches on the psychedelic nature of learning programming languages and what that does to one's perspective as a programmer.
So when you ask "what business thoughts can you express in the language", my response is it's not about what you can express, but more about "what new thoughts / ways of thinking has the experience of learning the language caused you to become aware of?".
Few people can go their whole lives writing Python and think all the possible thoughts there are to think about the shapes and forms programming can take. It's hard to develop a good sense for your own practice of programming if you never step outside and see it from other perspectives. It often takes exposure to completely new languages with different design points and abstractions to really give one perspective about their own practice.
The easiest one related to lisp is just the form of the syntax, which is surprising to many students. Most programmers don't even consider you can write (+ 1 1) and that's the same thing as (1 + 1). They don't think about the pros, or the cons, or why one might be better than the other, because every language they've used and ever will use writes it as (1 + 1). But as soon as they see Lisp, they immediately see something that changes their perspective about everything they have previous learned, and therefore will reshape how they approach programming in the future. It doesn't have to mean they will use Lisp going forward, but it does mean they will program in their language of choice with greater purpose. That's how we each hone our craft.
Add on homoiconicity, read/eval, programming as manipulating an AST, and meta programming, and you've got yourself a righteous trip.
Now, can people learn about those things from other sources, without encountering Lisp? Of course. Can you express those ideas in mainstream languages? Yes. But the point is many devs don't think those thoughts until they've had a psychedelic experience, it's very common, that we need to consider that it's part of one's growth journey as a programmer to have these experiences, so we should encourage it. The author of TFA doesn't have experience enough to make that point, as they are on the journey, which is why I brought Alan Kay's talk into context, since his perspective is from the other end of the journey.