I had the same feelings as the parent - this article did not make good arguments for using Haskell specifically in building production systems, it instead argues that Haskell is a good programming language yet many of the benefits listed can be found in other languages.

Even if Haskell was objectively the 'best' language, it'd likely be a poor choice for most teams simply due to familiarity and developer speed.

I'd be extremely hesitant to hire the services of this company entirely because they use Haskell and it'd be a nightmare to maintain after their contract.

I think the article was easy enough to pass by as I agree it didn't make GOOD arguments specifically in building production systems. I also give the author some slack because that article would be quite heavy to address the entire development cycle up to production systems.

From my reading the article makes no claim that Haskell is the best language. The purpose as I read it is to explain why Haskell is their first choice while addressing an audience that has a passing knowledge of Haskell.

You being extremely hesitant to hire the services because of their technology stack is great and fine. There are many stacks and services I completely avoid in dealing with so I agree there.

"It'd be a nightmare to maintain after their contract" is something someone would likely say to any language that is not their preference.