Why is Haskell seldom used, despite being considered a wonderful language?

A lot of computational problems are not math but interfacing, I think Haskell excels in the math related world and not in the interfacing one. This besides the steep learning curve, for myself personally a programming language is also a tool to help getting a mental picture of the problems to be solved. I loose much of the mental picture when using a functional language, but also when using a deep OO language. A functional language is too compact for me and a deep OO language too fragmented. Must be my deficiency, I cannot speak for others.

Because the only people who can understand monads are people who already understand monads. It doesn't help that people who think they understand monads try to explain monads to people who don't understand monads.

FWIW my definition of monad is also wrong. I treat monads as the equivalent of chaining. .do().this().then().that() and for most scenarios that way of thinking works. But I don't pretend to understand monads.

Don't get me wrong - I really want to like Haskell. But I've yet to find a monad explanation that didn't turn into "you understand monads when you understand monads".

And understanding monads is a pretty important step for writing good Haskell code.

it's too complicated when there are simpler alternatives

Elegant yet very abstract.