In my opinion the problem with Haskell is that terminology from computer language research (e.g. type theory) bleed into language which combined with sometimes appearing "elitarism" makes it just not very appealing for anyone not being deep into the relevant parts of computer since research.

I mean I don't need to know how engineers speak about the internals of my car to drive it (but it can be helpful), but Haskell kinda expects that.

Also it's not uncommon in Haskel to see functionality named not after what it does but after the theoretical computer since properties it has. Which might describe how you can combine it on a type system level but isn't that useful for easily writing programs and makes any "types as documentation" much worse.