I don't think I am. That code deliberately uses Haskell’s low-level features. It’s like saying, “hey, high-level languages don‘t even save you from segfaults! Just look at my purposely crafted low-level code in a high-level (but not dead, so it has low-level interface) language that access memory at 0.“
The author argues that using FP does not guarantee good code.
All that is necessary to prove that is to demonstrate bad FP code, which he has done. Only a single example is required to disprove a universal assertion.
> It’s like saying, “hey, high-level languages don‘t even save you from segfaults! Just look at my purposely crafted low-level code in a high-level (but not dead, so it has low-level interface) language that access memory at 0.“
If someone argued that high level languages save you from segfaults, your statement would be a valid argument against that, just as the article has provided a valid argument against a particular belief about FP.