However, I hate articles like this; they really don't help their cause, they sound driven as much by ideology as anything else, and in this case, there's even a financial motivation. It plays into the stereotype that Haskellers tend to find their language superior to any other, almost by definition. For example, many the benefits that the article touts would also be found in dialects of ML, or in Scala. However, many Haskellers I've talked to poo-poo these other languages because "they're not pure," or some other vague criticism. I don't mean to generalize, of course; many Haskellers probably embrace other languages as well, but it's certainly not uncommon.
Furthermore, Haskell is not at all without its warts: aside from its steep learning curve, it has package management issues and spotty documentation. Moreover because of its bizarre IO system (which mostly seems to exist for academic reasons, not for any practical purpose -- there are other, easier ways to disallow IO outside of sanctioned functions), it demands the use of Monads everywhere, and generally insists on a particular style which can be very restrictive. Last but certainly not least, its default laziness (once again, done mostly for academic reasons) can lead to bizarre performance issues, bugs which are hard to debug. The amount of hoops to be jumped through to accommodate laziness in Haskell is significant, to say the least.
Haskell has a number of great things in it. Functional programming on the whole is a blast to write and leads to very stable, readable code. But Haskell is far from the only answer. That said, it is a lot of fun to write, and its recent upswing in popularity is a very good thing, IMO, aside from the often pretentiousness of its users. At the least, it's raising the profile of functional languages in general, and opening the door for new languages which take the good parts from Haskell and leave behind the not-so-good.