> I'm pretty sure this is indeed largely caused by your Python bias. In my experience, Haskell code does not end up littered with Maybes.
I think the Maybes and other optional/sum types tend to be limited to the boundaries, where you do IO or handle errors, while your internal functions can deal with the concrete type. A code base littered with Maybes is certainly a code smell.
> A code base littered with Maybes is certainly a code smell.
It's not because Maybe (and usually more practical Either) have functor instances. What this means is you can use fmap to apply pure functions to Maybes, Eithers, or any other type that has a Functor instance.
I think the Maybes and other optional/sum types tend to be limited to the boundaries, where you do IO or handle errors, while your internal functions can deal with the concrete type. A code base littered with Maybes is certainly a code smell.