Sure, but the communities behind all the FP languages seem to share this same weakness. For obvious reasons, they attract people much more interested in hacking on funky compiler techniques than on mundane things like I/O libraries and documentation.
In contrast, I think Python and Ruby both owe a lot of their success to the people willing to put a lot of energy and polish into this essential but less glamorous work.
The Scala community is more of a blend on this front. It has FP aficionados, but it's also in production use and has commercial contributors focusing on practical issues. If Scala continues to gain popularity, it will probably continue to get more of a practical focus (there are only so many FP geeks in the world).
The other thing with Scala is that it compiles to bytecode; once compiled, it's just Java. And you can always use any Java library. So there's that base of a very solid JVM runtime and very solid ecosystem of libraries that's always there.
I don't know, this has not been my experience with Haskell at all. Not only do plenty of people work on all sorts of libraries (there are some really great web frameworks, for example), but they also work on all sorts of "less interesting" stuff. For example, there are some people working to improve Hackage, which is the site that contains Haskell's libraries and their documentation, and Haskell has really good support in Emacs (which is much better than good IDE support!).
I haven't spent much time with Haskell lately but the last time I did Cabal was still way less polished and useful than Ruby's gem system or even Python's pip/distutils stuff. Robust, easy to use package management is step one in getting any new language off the ground, IMO.
Around 2002-2003 I did put a lot of effort into improving the Common Lisp and OCaml ecosystems. My lesson learned was that there's only so much I can do as an individual and that the right kind of pragmatic culture has to exist beforehand.
In contrast, I think Python and Ruby both owe a lot of their success to the people willing to put a lot of energy and polish into this essential but less glamorous work.