It's really not the syntax that's the issue. It's the fact that the author of the article is embedding the category-theoretic concepts into the language at the

It's really not the syntax that's the issue. It's the fact that the author of the article is embedding the category-theoretic concepts into the language at the type level, so wrapper types like Id and FComp have to be introduced as "hacks" to represent functors. My main takeaway from this article is that at the end of the day Haskell is a programming language and not the most natural setting for abstract mathematics, even if there are many connections between the two areas.