I actually find it weird that computer games are thought of in the same vein as things like books. They're not. They're an entertainment product created purely to make money, by a company. And because they have such a short shelf life, the companies that produce them release them for free long before any sort of copyright would expire, making the issue a moot point when it comes to games.
Films, books, and music are totally different.
Uh, what? Are you insane? I assure you, Danielle Steele, Piers Anthony, and Martha Grimes do not write novels because they make no money at this. They absolutely make money. And people absolutely write books for money. Read old science fiction anthologies - see how often authors discuss turning out a particular short story for rent money, or something similar.
Video games are absolutely as much of an art form as film, books, or music. Yes, Call of Duty 2 and Spider Man were probably made because they figured that they could make lots of money making it. I doubt any film director really thinks that he's contributing something deep to the art world when he makes a film about cars that turn into robots, a kid who can swing through a city, or a British super-spy. Similarly, companies don't turn out games like Modern Warfare or God of War III because they think they'll tell a deep story. Does the existence of 'Spy Kids' call into question the quality of 'Citizen Kane?'
What defines art? Is it ability to inspire emotion? I assure you, people have felt as deeply about the death of Aerith, the effects of war and what you have done to help/hinder it, or the anger you feel as an injustice is perpetrated.
Is it ability to ponder philosophical questions? You make the choices in many video games. You can choose to release a potentially life-ending intelligence back into the 'wild,' or commit genocide. You watch the results of your actions play out before you.
Is it that you passively view the work of an artist, take it in, rather than interact with it and change the experience through the interaction? Many artists would prefer their pieces to create a dialogue between the viewer and the artist, a shared and personal experience.
I actually think that it is the last. The idea of 'active art' rather than 'passive art' has always been controversial.
P.S. The nature of the medium is that as technology improves, the ability to realize creative visions improve. I'm certain that you agree that the advance from black and white to color film advanced the ability of artists to recognize their vision in film. Similarly for CGI, scene changes, 'chase cams' (high quality portable video cameras), stunt technology (pyrotechnics, rigged collapses, etc.). Actually I can point to an easy one - the CGI resampling of flame complexity enabled directors to burn models while maintaining realism - which allows burning buildings to effectively function without the eye-rolling induced from the obvious model burning. Something effectively impossible before (it ALWAYS looked like a model, due to the lack of flame complexity at that size).