If you did a little research you would know that Tolkien meant 'The Hobbit : There & Back Again' book to be a one-off. When he wrote this, he had no inkling that it would become the prequel to LOTR. Thus all the characters in there were in no way developed as part of an epic sweeping tale like LOTR was.

The tone of the book was very much lighter and being a children's tale, there is not much killing and vengeance underscoring the characters' motivation.

It was a pretty straight forward adventure tale with Bilbo being the central character through which the reader is being shown the story. As such it made sense that none of the dwarves were killed.

When LOTR came about, Tolkien had expanded the universe of Middle Earth to such an extent that 'The Hobbit' came as a bit jarring in comparison. LOTR had a much darker tone. Doom and gloom all around. The simple gold magic ring that made its wearer invisible had become The One Ring. If Tolkien had written The Hobbit as part of the LOTR lore from the beginning, it would have been a very different story.

That's the problem I think Peter Jackson had. He was making 'The Hobbit' but he wanted it to tie in to his LOTR trilogy. He wanted to make it seem like it was part of the same lore right from the beginning. It just didn't come off very well.

If you remember by the end of the Fellowship in LOTR, Gandalf had fallen, Boromir was dead. The fellowship was broken. Everything was going to hell. The threat was real. You could feel the doom, the sense of despair.

Peter sought to bring the same sense of doom and threat to The Hobbit. It just did not come off right. All of them survived the ordeal with little more than a bruise at the end of the movie. He could not kill off any of them because they did not die in the book but he made the battles seem so desperate. He made the threats so big like giant rock monsters as big as the mountains themselves battling it out. Like facing thousands upon thousands of goblins and being pursued relentlessly by Azog, the Orc that was not even in the book in the first place.

That is why I say Peter Jackson was trying to make it epic. I don't know. I was not expecting that. Perhaps most of the fans of the LOTR trilogy were.

If Peter had just made the movie more like the original story - a straight forward adventure tale that so happens to have the One Ring in it, I would have been quite all right with it. I could tolerate 2 movies but 3 is really overdoing it judging by this first movie.

In the tale/appendices as written by Tolkien:
Azog was killed by Dain (Thorin's nephew) after Azong killed Nain (Thorin's cousin, Dain's father) in a war 9 years after the beheading of Thorin's grandfather. long before the events in the Hobbit.

Bolg, son of Azog will be involved in killing Thorin which is later killed by Beorn (a character to be intro in 2nd movie) in the Battle of the 5 armies.

The Movie triology:
With Azog still being alive... The Question is how is he going to die? and at whose hand?....
and how Bolg (a confirmed character) comes in to revenge...

I suppose different time-line of events... but same end result... like LOTR...

Azog should already be dead