Search or post your problem in the appropriate forum here; you should get a responce in considerably less than 2 weeks.
Why do other games have backgrounds displaying objects that you can not do anything with?
While rocks themselves don't add a great deal to the game, they do help make the environment more interactive (which many people actually like), and can probably be thrown at monsters (since I have seen posts where people have thrown barrels or vases at monsters to do damage).
