School Library Journal carries a response to Has the Newbery Lost Its Way? called The Newbery Remembers its Way, or "Gee, thanks Mr. Sachar." The point of this second article is that the Newbery is awarded for literary quality. That isn't necessarily the same as readability, though it certainly can be.
Unfortunately, a lot of people outside the library and literary world aren't aware of what the Newbery is supposed to reward. Thus the disappointment when it goes to books that are well written but not necessarily of a type that will draw in crowds of readers. (Whatever that "type" is.)
Personally, I can accept that the award is for writing and not, shall we say, the kid appeal of the content. But I think the Newberyites need to also accept that some years there's going to be a gulf between their choices and readers.
That's not a bad thing or a good thing. It's just a thing.
The original article is being discussed at one of my listservs as well as at Read Roger.