—Far from it. It's the resolution of a lot of foreshadowing in the trilogy itself. Originally, Frodo (as does his uncle Bilbo before him) complains about how stodgy and boring everyone in the Shire is, about how they're so bourgeois and complacent, and how they need a little shaking up — sometimes he wishes they'd have to deal with real dragons for a change!
Then he goes on his quest, and there are worrying glimpses that all might not be well when they go home again — a real life problem in WWI, and in WWII (and I am sure back to the days of Rome) for the soldiers, who had this dream of everything perfect and preserved for them to go home to, the lamp in the window and the apple pie and the happy family, not realizing properly that war would touch and change "back home" too.
One of these was cut from the FOTR movie: after the Council (very different from the Movie, and not simply by reason of cuts), Elrond wants Merry and Pippin to go back to the Shire in case the War goes badly — he wants some hobbits there with knowledge of the outside world, and the bravery to take direct action, and leadership qualities. But Gandalf overrules him, and says they ought to go with Frodo if they really want to. But this will come back to haunt the Quest.
Another one was the fact that Sam as well as Frodo is invited by Galadriel to look into the Mirror, since he's been saying he'd like to see some "Elf magic" — though she warns him that information can be dangerous, you don't know what you'll see or learn, (a very good "real life" point) and that a Seer's gift is most useful when you don't try to control what the vision shows you (another useful real life lesson about not filtering your data to tell you what you want.)
What Sam sees is a vision of his neighborhood being torn up, all the trees cut down, all the houses dug up, and his dad being evicted. This gives him a moment of moral crisis, because if he stays on the Quest, he can't go home and help. But is it a real vision? Even Galadriel doesn't know. The things you scry in water (or in crystal balls!) might be true, but they might also be alternate futures. Who knows what actions will change them?
Then, in TTT, Merry and Pippin find barrels of tobacco in Saruman's private warehouses. This is pipeweed from the Shire, from their own neighborhood, recognizeable by the "Hornblower" brand name (literally branded, in this Age) on the barrels. They just think this is a really nice coincidence for them, but Aragorn the Ranger, who in the book has been one of the secret guardians of the Shire for so long, is troubled by this "coincidence." But again they have no way of researching this (no telephones, no internet) and there's nothing they could do anyway, it's TEOTWAWKI time.
Then, after all is over, when the survivors go home after the War, they find that things have changed in the Shire while they've been away. Saruman has escaped from his house arrest in Orthanc, and sneaked over to his contacts in the Shire - the people who were getting rich from the private import/export contracts he was arranging so they could sell tobacco outside the Shire. Some of these are actually Frodo's relatives. While they've been away, Saruman has set himself up as a mini-dictator using Frodo's cousin Lotho as a "front hobbit" and turned the place into a police state. Because of their unorganzied, individualistic society, and because they were so complacent about the outside world, the hobbits at home had no idea how to cope with this.
Remember how Elrond wanted to send Merry and Pippin back home to have some hobbits with a wider outlook and the courage to take bold action in place in the Shire, in case things went really bad in the War, there'd be someone there to try to keep things going? Well, it could have been worse, but this is pretty horrifying to Our Heroes. They have to come in, set up a resistance movement and teach their fellow hobbits how to organzie and defend themselves, not stand around bewailing how bad things are getting, while thugs from outside, and corrupt fellow-halflings, turn life into a hell. There is a lot packed in here about justice, mercy, and not turning your homeland into another Bosnia, but even though Saruman's defeated completely and his Big People mercenaries routed, it's a bitter thing for them to come back to.
Like the saying goes, "You can't go home again."
And it adds a nice touch of moral ambiguity* and more shades of grey to an already-complicated book: instead of thinking of corruption and greed and conquest as something "out there" and foreign, the realm of the Bad Guys, to come home and find that no one is immune, that your neighbors can sell out too, and your own people are just as vulnerable to some temptations as anyone else, is a bit of a shock. But at the same time it allows Our Heroes to demonstrate how much they've grown up, and show their new leadership abilities, and the lessons they've learned in the war-torn outside world, by taking care of their own wounded homeland afterwards.
For many readers, this bittersweet ending is one of the things that makes the trilogy so strong — it doesn't end with a sappy Hollywood "happy ever after" but with a "life goes on," unresolved note. The fact that Jackson reportedly never liked it is (to me) one more indication that he just doesn't get the books, the fact that the ethical issues and the character development are WAY more important in Tolkien than big battle scenes. But I was extremely disappointed with the way Two Towers was handled, so I'm not surprised that in ROTK-M this complexity too was sacrificed (and its space given to yet-more invented battle sequences involving CGI.)
I know many readers don't like it — but it's not supposed to be likeable. It's supposed to be disturbing. The world has been broken apart: it can never be fully repaired. We have been burnt in this war: we will never forget it. This is not, at the truest level, fantasy, any more than Crime and Punishment is fantasy. Fantasy is a happy ending where all that's bad is done, over with, in the past and quickly forgotten. Reality is when the consequences of past errors and of choices good and bad, all echo on far and wide through the lives of those that follow forever.
As the characters in ROTK are still hearing such reverberations after
more than three Ages of the world…
Ironically, the same reviewer thinks that this is an example of a refusal to dumb down and bow to the conventions of H'wood, where, presumably, the Enemy is never demonized and the Heroes never shown as gooder than good (we all remember that morally-ambiguous recent hit, The Patriot, wherein the main character's historically documented slave-raping and human-hunting habits were allowed to contrast with the noble humanist principles and tormented duty of the British officer who opposes him... /irony.)
I think we must have read different versions of LOTR, from alternate universes maybe, because it doesn't sound like the reviewer read the part where Sam wonders about the motivations of the dead Man fighting for Sauron, and about the enemy soldier's family, or where Sam considers that no one is the villian in their own version of their story, not even Gollum, to himself — and the reviewer certainly never read Tolkien's own meditations on the nature of heroism, Frodo's fall, Sam's flaws, and how not even Gollum is necessarily damned, though it sure looks like it, because we just don't understand from outside the nature of temptation as it is experienced by another soul…