Good grief, what a vast amount of supposition backed up by very little evidence or insight. "People often write bad code." Yes, we know that. "There's more than one reason for this." Yes, we know that too.

The rest of the article is just random presumptions thrown together, for what reason I couldn't say. The best developers work in finance because the money's highest? Yeah, OK then... (To be fair, I think there is a qualifying "considered to be" in there somewhere) K is impenetrable? Hmmm. Haskell is an offshoot of ML and unreadable? Umm, factually wrong.

There's lots wrong with software at scale, and the pressures of financial institutions along with high budgets etc do produce an interesting set of problems, but this article offers nothing new about anything at all in the field.

As an aside, I already don't trust an author when they start off with a claim that textbook code is good code! It's almost universally accepted to be trivialised and simplified to the point of "don't do this in the real world" simply because it has to be. Some of the worst code I've seen has been in textbooks (and that's worst as in "dangerous" rather than as in "badly written and in need of refactoring/replacement/enclosing in concrete).

Edit to note: I think it's actually beyond incompetent journalism and in to plain lying to present a piece of code as evidence of Haskell unreadability when the link to that code on SO refers to it clearly as "obfuscated Haskell code".