There was too much killing (!) He was wondering why they had to kill everything they came across: trolls, goblins, wargs (which he thought were wolves; he did not like it when he thought they were killing animals)
I actually had the same feeling, at times. Not because I have issues with movie violence as such (I guess I play too much evil videogames), but because it felt we were leaving the cartoon violence territory and crossing into the real violence territory in scenes that still had too much of a fairy-tale feel, and the fairy-tale elements and realistic elements didn't mix well in those moments where more realistic violence had to be shown in order for us to believe the dwarves were fighting for their lives.
For me, this was very apparent in the the trolls scene. Their appearance, the snot joke, the funny voices, smacking each other with saucepans, dwarves in their undies (later), all this indicated a light, fairy-tale tone. Then suddenly the dwarves run in and start this fierce, brutal fight. Even though there was no blood shown, I found myself wondering if this was necessary, and I felt sorry for the trolls because after all, they were just hungry.
Goblintown suffered a little bit from similar discrepancy in my opinion, but at least we know the goblins are essentially evil. It wasn't a huge problem for me.
Granted, I think the Trolls scene might have been the most difficult in this respect and from now on the more realistic violence should't be causing too many issues. We crossed the Misty Mountains, we're now past the funny Trolls and cartoony Goblins, and we'll be dealing with dark and evil spiders, orcs, dragons and... um, zombies.
As for killing the Wargs - I understand why would anyone feel there's too much killing here. I'm kind of sensitive to the whole wolves/hyenas = evil prejudice, even if they are magical half-wolves.
Felt that The Company was totally useless and kept getting themselves into trouble and always had to wait for Gandalf to save the day.
Hehe, too true :)