The code behavior is obvious once you know Haskell. The code simplicity confuses people that don't know the language and think it is something much less powerful than it actually is.
We actually did for a long time. It wasn't so bad, I guess? Certainly not worse than Python, to me.
But the value of writing this kind of code in Haskell is that Haskell makes code that couples very abstract interfaces VERY easily. This is really hard to explain without some examples, so I'm going to give you an example.
What's cool about this code is that I'm describing a "generic" radAPI service with a bunch of endpoints stripped out. Everything is parameterized around 3 generic ideas: "p", the Storage service. "Patchable", a strategy for applying patches to a storage service (exposing runPatch), and "CanValidate", a strategy for authenticating requests based on some sort of stored string, auth headers, and body contents.
This is even better than mocking, because instead of deeply coupling the structure of my code to my tests, I only couple the capabilities.
