Your post implies that the main reason people would use an IDE is because they are having trouble getting non-IDE tools for the language setup.
Of all the benefits I've heard ever used to sell IDEs, that's got to be the least common. Usually, things like syntax highlighting and error detection as you type, project management tools, version control integration, autocomplete, documentation/API tooltips, debugger integration, etc. are the advantages.
Some of those might be less relevant to Haskell than to, say, Java/C# style languages, but some of them would still be useful.
My impression is certainly that IDEs are aimed at beginners and users of more 'complex' languages like Java. (Case in point: Java has DrJava and other beginner IDEs, as well as IDEs for professionals like IntelliJ.)Indeed, I was referring to the the claim of the OP that "you don't need to mess with setting things up", which, to me, seemed to imply that it was a significant hurdle to get started with Haskell using an editor and ghci.
Syntax highlighting is part of any editor that is aimed at programmers, the interpreter does a great job highlighting errors, version control is done with git, and there is plethora of documentation on Haskell available too. Normally, ghci satisfies that need as well.
IDEs exist because they give you the full, bidirectional power of the compiler at your fingertips as you type, complete with annotations, jump-to-definitions and other code navigation, and syntax tree transformations (as opposed to just textual ones). If you think syntax highlighting, version control integration are top features you are sorely mistaken.
The fact is, you CAN do many of the things an IDE can do without one; its just generally harder, less discoverable, slower, takes longer to master, and for no real benefits. I would rather have a text box pop up saying exactly what types something has, and all the documentation about those types, and where it is defined in code, directly within my code in 0.1 seconds, then have to go and run some grep or hoogle search or whatever.
Scala is arguably part of the group of 'complex' languages I mentioned. Besides, the Scala worksheet functionality in Eclipse is really neat, which is another reason to consider using an IDE for it.
Of all the benefits I've heard ever used to sell IDEs, that's got to be the least common. Usually, things like syntax highlighting and error detection as you type, project management tools, version control integration, autocomplete, documentation/API tooltips, debugger integration, etc. are the advantages.
Some of those might be less relevant to Haskell than to, say, Java/C# style languages, but some of them would still be useful.