Haskell is _not_ inherently hard - any more than any other programming language. But it is different. So right now, Haskell is hard only because we need more documentation that is designed to make Haskell seem easy. Well, I think it's harder to get a program compiled in Haskell than in Java, for example. It's not too hard, although debugging might be a little difficult. I think this has to do with the type system. Althought it sounds bad, it's actually a good thing. Once you get a Haskell program compiled, chances are much higher that it's correct. You do a bit more work up front, but chances of a bug are way lower.
The way I see it, programming in Haskell is an investment. If you're from a OOP-background, some (trivial) things might take a lot more time. But in the end, it does make you more productive. You spend less time tracking bugs, and it's easier to refactor. Not everybody is willing to make an investment when they've got something that works. For example, if you know one imperative language, you can switch to another without taking too much risk. On the other hand, if you switch to a language that is completely different, you don't know if it will get your job done. It doesn't feel safe. -chris