The Hobbit book has a much lighter, humorous atmosphere than the Lord of the Rings. Tolkien wrote the Hobbit years before he created more of Middle-earth's history; he wanted to rewrite it after he completed Lotr, but never did.
Keep in mind that The Lord of the Rings is about the possible destruction of all of Middle Earth by an extreme evil while The Hobbit is about a bunch of Dwarves and a Hobbit going off to get back some gold and fight a dragon. There is importance to their quest, but it does not hold nearly as much weight as The Lord of the Rings.
If they fail, maybe they die, or they simply don't get their kingdom back. If they failed in LOTR everybody was going to die or become slaves and all of Middle Earth would be in ruin. I appreciate that Jackson is taking his chance to add a lot of extra info into The Hobbit from the LOTR appendices, but The Hobbit is, as many have said, written for a younger audience. Tolkien even considered going back and rewriting it in a more adult form to match LOTR, but he decided not to because The Hobbit is simply not as heavy a story. And that should not be a mark against it.
Also, another director did have the reins for a while before Jackson returned, and he is credited with that work, that's why it doesn't feel exactly like LOTR. If you know Del Toro's work (Hellboy, Pan's Labyrinth) that makes a difference too.
You expected Hobbit to be like Lord of the Rings. But The Hobbit is NOT Lord of the Rings and it SHOULD NOT BE like Lord of the Rings AT ALL. Read the book.
That being said, I too found The Hobbit to be An Unexpected Failure. For other reasons, of course. Starting at the beginning, was that flash-forward to Lord of the Rings necessary? Nope, it was not and instead of random orc chases (more later on), the story about downfall of Dale could be told over some campfire in order to bring some action into the movie later on.
Next, Azog the Goblin is mentioned not even once only once or twice in the book, and Thorin hints that Goblins in the Moria were dealt with. In the movie, Azog iz apparently very much alive and wants to avenge his hand by killing Thorin and everyone that's around him. This unpleasant thing results in orcs randomly popping up because Americans can't watch a movie that contains low amounts of action (with exception of some specific genres). That "le avenger" subplot is so basic and with no work done on it... Seriously, I thought such shitty (sub)plots are gone from AAA movies, but I figure UAJ had proven me wrong.
Another side effect of that is that Goblin King is no more than a mercenary and - yeah I do know that Hobbit is not supposed to be über-serious, but the amount of fail humor in that section is too damn high! I don't have a problem with Peter turning the goblin tunnels into a cave that's big enough to contain Tyria, Tamriel, Narnia, Azeroth and three quarters of Ferelden, though, but I dislike how the pursuit in the said cave ended. There's tons of better ways to end a chase than breaking almost whole physics and cherrying that up with some more fail humor. About at that point I managed to realise that the movie won't really completely live up to my expectations, but the worst was yet to come.
The ending. It's... An unexpected letdown, failure, soap, lemon... Does anybody else recall what the book had to say on that matter? Yeah, that's right. Fellowship runs on trees, wargs surround them, Gandalf instructs them to trow some cones and goblins then torch the trees they're on with the cones. Tolkien keeps subtly inserting his Christian agenda at that point and provides them with get-out-of-jail-free card. Eagles come and take them to safety. Compare that to what happened in the movie: wargs come, jump on trees till they fall and dwarves + Bilbo + Gandalf eventually reach the last tree before the cliff. Fire cone throwing party commences and ends when the tree ends up leaning over the cliff with two dwarves almost falling off. Thorin then decides that it's a good moment to Leeroy at Azog, who then totally pwns him. He then orders one of his minions to make Thorin a head shorter. Good Guy Bilbo notices that and goes Blitzkriiiieeeeeeeg!!!! at the minion, killing him not quite softly. WHAT THE FUCK, PETER, WHAT THE FUCK!? You know what Bilbo and Columbus from Zombieland have in common? Yes, it's rule 17. Don't be a hero. And, guess you hadn't noticed, Bilbo is not a hobbit of big deeds - Congrats, Peter, you've just totally screwed Bilbo's character. Then shitstorm breaks loose, eagles manage to rescue the company later than the last moment possible and carry them away, to some place where they can see the lonely mountain. At that place, Thorin gets okay enough very soon and does to Bilbo what Stoik has done to Hiccup after he found that his son just reached a new record in bashing one's own head against the rock. For those who don't get the reference, that means: "Oh sorry Bilbo, I thought you are a piece of shit and the greatest fucktard I've ever seen, turns out I was completely wrong and you're not a fucktard after all" + a hug that lasts one eternity and a half. And this... this is where this movie fails the most.
In translated version, word 'orc' is not mentioned only once or twice (and interchangeably with word 'orc' for that part). And as far as I've come with English version of the Hobbit (pocket edition), I haven't seen word 'orc' being written yet. And Azog is/was a goblin too.
I suppose it's possible in some of the earlier drafts, but I've read everything Tolkien that I can find and haven't yet found such a thing, though I haven't yet been able to read all of the Histories of Middle-Earth. Even if they weren't quite synonymous in a few cases, though, I think they would likely still overlap some.