The main issue is that Haskell is not a data-oriented language by default, this means its no fun to push it to be that. For example, I also have to use java in my job, I use persistent (functional) data structures all the time, but Java is not built for it, its not fun. (Although definitely more fun that using Java's mutable structures, ewww)

Also I personally find that to be too much overhead and ceremony in return for some type checking at compile type, as opposed to spec checking at runtime.