It's humorous because of all the changes that were actually made in the movie DoS, and act as a sort of unintentional (unless Tolkien had the gift of foresight) foreshadowing of PJ's many changes.

But there's a difference between the majority of changes to the LoTR films, which I was mostly fine with and were there for convenience's sake, and the Changes to the hobbit films. In LOTR, the only problems I had with changes were the Elves at Helm's deep and the army of the dead. Just look at the scene where Gandalf is comforting Pippin when the Troll is hammering the door in ROtK. How is that screwing up his deeper messages? Or sam's speech to Frodo at the end of The Two Towers - really good capture of Tolkien's spirit I thought.

Whereas the hobbit has added Azog's storyline to the films, created Tauriel for no good reason WHATSOEVER apart from "we need a girl". Compare her to Eowyn and Galadriel and you realise how sexist Tauriel is, always mooning over Legolas and Kili.
The plot has had major changes - action added in for its own sake, but in a tasteless manner. I liked the film but I felt it could have been as good of an adaption as LOTR but failed. The film's superficial failures (CGI orcs which look cartoony) cover up its fundamental failures (why on earth does Legolas get more than a cameo?)

Hobbit- Mega Changes, Decent Film
LoTR - Few Changes, Exceptionally Great Film.
Corrolation PJ!

Yeah Arwen's weak, but she is the exception. Eowyn(kills the witch-king), Galadriel(runs a country, her hubbie is barely mentioned), even Lobelia (utterly fearless) - all are three dimensional characters. Tauriel has "I like Legolas/ I like short guys".

Have you seen X-Men: First Class? Wolverine had a short (and not very polite to poor Prof. X) cameo in that and it worked wonderfully. If Legolas had gotten that in this film it would have been great.
Maybe I'm being too harsh on the Azog thing; alone it would be tolerable but with everything else being changed it just doesn't work for me. The Necromancer on the other hand was one of my favourite scenes in the film. The more flash thing is my entire problem - it doesn't fit well with the original trilogy. If anything there should be less of an emphasis on violence and more on character. The two best things they've done are Thorin's character arc and the overall acting quality and both are great, so maybe its not all bad...
The Hobbit is much more of a children's book than a older book in my eyes. But that doesn't mean it lacks meaning. Like the Chronicles of Narnia, it's a kid book that you don't grow out of, but grow up with.