Exactly. I did get the impression that the author is more familiar with OCaml than Rust. However I don't think they were claiming Rust's greater low-level control makes it inferior to OCaml in general. They're just saying it makes it less suitable for writing compilers, since (in the author's opinion) this level of low-level control isn't necessary for that task.
that's the point of the article - rust gives you a lot of low-level control, but if you don't actually need that control then you're paying the cost in ergonomics for nothing.