it was also a miracle because despite being a lifelong fan, jackson showed every indication of not really understanding the source material (extremely common among lifelong fans). the extended cuttings are a rape of tolkien's vision. but somehow the majority of that stuff got left on the editing floor, and the remaining changes, while untrue to the author's vision, are for perfectly understandable hollywood reasons.
the biggest one is something the essay talks about a lot -- aragorn is given a character arc, because in recent fiction and fantasy, there are no perfect protagonists. this was necessary for the idiocrats. in tolkien's book, of course, the hobbits are the main characters, and they have excellent character arcs. but hobbits aren't hot, and tolkien - the fool - didn't write any hobbit love stories into existence. so what we saw was what we got.
of course, this author also said some things that are just wrong. i'm reminded of the old line -- any time you read journalism on a subject you know well, it's clearly wrong in lots of places, so why trust any of it?