I have to disagree about LYAH here.
Allen can argue that LYAH is incomplete, and he seems to think the university courses he mentions are the best way to learn Haskell. But not all developers want to go down that route, at least not as a first step. For me, LYAH was an important stepping stone to getting productive, while at the same time fully understanding that it was not the final word on anything.
This is, I suspect, what Allen doesn't get. His Haskell book is actually yet another example of why many developers find Haskell daunting to learn; it starts at the deep end, like many books before it. LYAH succeeds precisely because it doesn't go into several pages about beta reduce before explaining how variables are declared. Sure, it's chatty, it likes to rely on the REPL to show evaluations, and it also doesn't start with a formal introduction to functional languages or lambda theory. But it's a book written for programmers who already know how to code. It's approachable, doesn't go into unnecessary detail (if you want to know everything about List, go somewhere else; the Haskell Book has 59 pages devoted to it!), and lets you get up to speed fast without falling off along the way. It's an introductory mini course, and by the end of it you'll be able to write programs.
I don't buy Allen's arguments about it being "unpedagogical". I've never used book exercises and I never will, yet I didn't have any issues learning Haskell, or any other programming book for that matter. The absence of exercises in LYAH doesn't make it a bad book.
As an aside, Allen co-wrote what he claims is a superior book, and then published it as... a PDF. I just purchased it, and was immediately disappointed I had paid $59 for what amounts to a paper book in digital form, with no web version (the "online" version on gumread.com doesn't even provide hyperlinks within the book). LYAH is great because it's adapted to the web. I'm sure the Haskell Book is wonderful (and I'm reading it), but this is another way he misses the point of LYAH.