My take on Haskell is that it’s just a toy language that has a very steep, uphill, rocky learning curve. This makes it ddifficult to make real products with it, along with the overwhelming number of idioms in the language.
I agree that the learning curve can be steep if you’re not familiar with some of Haskell’s underlying concepts. But what makes you say that it’s a toy language? Many people are using Haskell in production systems.