I think the main difference is in scope: to use node, you basically write code as you normally would in JavaScript, which is not entirely dissimilar to languages almost everybody is familiar with. It is different, but not by much. Writing a program, particularly anything interesting, in a language like Haskell is entirely dissimilar from anything most people have used. F# is probably also like this, but I'm not familiar enough with it to be sure.

The point of trivial examples like quicksort is just to illustrate the fundamental differences--mostly advantages--of using functional languages. Using a functional language will change every aspect of your code, so even examples like this are illustrative while being simple enough to fade into the background.

Languages like Haskell do have a ton of cool features, but they are all overshadows by how different they are. Once the fundamental differences are thoroughly explained, other goodies can emerge. For example, look at snap, a really fast web framework for Haskell. It's even faster than node.