Not the OP, but I don't think Haskell will ever be drop-in replacement for mainstream langs for cultural reasons, but that doesn't mean that those who do engage w/ it don't get get tremendous value from it or fail to find it their favorite language (I.e. Doesn't contradict what willtim said). And I think that's OK. (No, you're probably not going to convince a bunch of rubyists to use haskell). You can even train entire teams of willing Haskell developers from scratch, if needed. But the desire / buy in has to be there. IMHO anyways

Part of the problem is that dev is so large that it is hard to make "in general" statements anymore.

It's easier to talk about concrete/specific instances or cases