They're showing off in a holier-than-thou douchey way.
Contrast that with the attitude the folks at freenode#haskell sport, who are actually solving hard problems, and you'll understand why I think MojoTech's blog post is immature.
That's cute, but my point is not about Haskell, but about the new grounds computer scientists are breaking using Haskell as a tool. Those are seriously hard problems. Making a phone app is not hard.
