I think it comes down to the specific codebase for the Clojure version vs. the Rust version. In this case, after rewriting the code into Rust it was easier for the author to understand and reason with.

Not that you can't do it in Clojure or any given language.

In the end, they're happy with Rust. I really like what little Rust I've done. I still reach for JS/Node first only because I can get something working faster often because of what's in the box and in npm. It's far from the most performant, but often fast enough. C# tends to be my second level, though as I become more familiar with Rust, it may displace this.

You can't be an expert in everything and sometimes a given language will lend itself to the way you think in idiomatic terms.

The article is an anecdote on a personal experience, not an assault on Clojure or the ecosystem. Even if it is critical at a couple points.