IMO the movies needed to set up a reason for the animosity between the Wood Elves and the Dwarves of Erebor, not rely on ancient history known only to book fans.
That's a fair point, though Thorin's attitude was a bit extreme, extending to all Elves including Elrond's folk, who--when they lived in Eregion--had had a good relationship with the Dwarves of Khazad-dum (Thorin's ancestors).
Thorin in the book had none of the animosity toward Elrond (or even Elves in general) that movie Thorin displayed. Thorin was your basic proud old man/dwarf fallen on harder times than he’d like to admit. He took offense to Thranduil’s questioning (and compounded that with innate dwarves greed). Movie Thorin hated Elves to the point of unreasoning racism.
Just one more reason my joy at the start of AUJ with the “Good Morning” scene quickly turned to dismay and revulsion as the movies progressed.
