New Haskell developers spend a bit of time figuring out why the types of an expression aren't what they think they are, especially when wading into using some of the libraries with more sophisticated use of types.
I'm not certain what you're asking. If you mean it's unfair to compare experienced Ruby developers to new Haskell developers I agree, I was just explaining where the sentiment was coming from (insofar as it was legitimate).
You're assuming that difficulty is a single constant, which is definitely not the case. The real state of things is that Haskell is more difficult than Ruby to get really good at, but the actual work of developing things in Ruby is much more difficult than developing things in Haskell. This is because when you develop things in Ruby, you spend a lot of time debugging heisenbugs due to the total lack of referential transparency.
Accordingly, yes, newcomers to Haskell will probably have difficulty understanding what the type system is telling them, and this will slow them down a bit. But analogously, newcomers to Ruby (especially those using a heavyweight framework) will have difficulty figuring out why their application is doing what it is, and this will slow them down a lot.
(Source: I've worked professionally in both languages.)
