Reckon the judge in the case I linked above disagrees with you. The notion of incidental use is important, as well as a formidable defense against accusations of copyright infringement. Like any form of self-defense, you've gotta have nerve to rely on it. The example that always leaps to my mind is the game series "The Getaway," in which turn of the century Central London is recreated all the way down to a remarkably complete assortment of cars you'd be likely to find in that period and setting. Now guess how many carmakers the developers got licensing from.