I used to program in Haskell for fun and school and I liked it. I find it very well thought out language. I may very well come back to programming in Haskell when I encounter a suitable project.
But there is a tendency among Haskeller's to get too caught up in praising purity and laziness, while ignoring the nice practical aspects of the language that could enable it to rise to be an even greater language.
I'm not saying that author is guilty of this, this is just a general observation. And I must admit that I'm not quite up to date of what's up with Haskell. My point is that Haskell is great for reasons other than purity and laziness, too.