I seriously disagree.
Art pieces in games, such as plots, narratives, cutscenes, and even movies, can be considered art. In its purest sense, what are the goals of these static, non interactive set pieces in video games? They convey a message. If movies are considered art, then the CG movies in Final Fantasy is art. If the many forms of literature are considered art, then the intricate dialogue of Visual Novels, and even the codec moments of MGS are considered art.
The argument is, even if a video game has numerous art pieces, it cannot be considered art.
So when can a game be considered art? EVERY PIECE OF DEVELOPED SOFTWARE IN FORM OF A GAME IS ART.
First of all let's define art, let's use wikipedia's definition...
"Art is the process or product of deliberately arranging elements in a way to affect the senses or emotions. It encompasses a diverse range of human activities, creations, and modes of expression, including music, literature, film, sculpture, and paintings. The meaning of art is explored in a branch of philosophy known as aesthetics. "
All forms and pieces of art deliver a message. The difference of delivering a message or expression between a movie or an essay against video games is one simple fact. Video games are supposed to be interactive . When you watch a movie, when you read a book, do you believe that whatever reaction you emit will have an impact on the message that is being transmitted? Will your actions affect(the only action is, to read or to watch) the way the story is presented? NO. Why? It's because a writer has already written a plot for you. All you need to do is watch. Entertainment just follows.
All you can do is watch, observe, analyze, and decipher the message on your own after watching. In video games, especially the video games of recent years, players now have a choice. And their actions affect the flow of a game, even if the game is linear in nature, or even if it's just a casual game without a plot and a point to spread across.
If you have played the recent Final Fantasy XII, you know that its a very strict, story driven game. While there is only one message at the end, you have different methods to get there. The case is simillar to Diablo or any other RPG(even MMORPGs). The development of the characters in terms of gameplay are left to the player. If you novelize everything, say write your progress in excruciating detail (meaning you will tally how much potions you have in your inventory, or your exact weapon names), and you compare this to other people, you will realize that no experience will be the same as any other. Sure, in order to get to act V, you have to pass acts I to IV. And you can never change the way the story goes. But the way you approach things, the way you get through the challenges, is a unique experience that belongs only to you. I'll put in a simpler way, playing and finishing a video game is like reading a novel, albeit interactive. In as much as you did not contribute to the story and its resolution, you uncovered the pages in a different way and still got the message in the end.
This is not art, yet...
Ok, let's move to a less serious tone of things. Let say, Plants Vs. Zombies. While there is a plot(zombies like brains, plants hurt zombies), it's not necessarily a core aspect of the game. Its just there in order to spice things up and create appeal(Without the quirky zombie theme, i wouldn't play this and would just stick to my tower defenses in Warcraft 3, some have far better mechanics than the one PVZ uses).
The difference between plot-driven game and a casual non-plot driven game, is that, casual games focus on the experience rather than giving a message. Every movie, photograph, and piece of writing has a message to say. Casual games do not need to give off messages, for their main purpose is to entertain. Any plot that comes afterwards, is just a theme, a design for aesthetic purposes. If you remove the terrorist-counter terrorist them of Counter-Strike, it's still an FPS with modern urban combat elements. If you remove the plot of God of War 3, it's no longer a cinematic gaming experience, just a soulless hacker-slasher...
So what is the difference between Games and other "legitimate" forms of art? Experience.
To experience a movie, you will have to watch. To experience a novel, you will have to read. To experience accounting, well, you have to study? Forget that one.
Video games are meant to be played. Once you finish playing. You will always have a reaction. A stimulation of the senses. No matter how linear, or story driven a video game is, it is experienced by a user in a different way to that of a movie, literature or music. And the experience is not controlled. Essays are read word for word, guitar instrumentals are heard chord for chord, and scenes in a movie will always be the same no matter how many times you play it. In a video game, the experience is left to the player. Although the story, the environment, and the presentation is beyond your control, how you approach them is entirely up to you. Are you a juggler or a button masher in Tekken? Do you prefer CQB or Sniping in CoD4? Do you build up your army, or do you rush your opponents in Starcraft? When you finish Tekken, you get a CG flick. When you finish a round of Domination in Cod4, you get bragging rights. The end result is the same. But you will always have a different story to tell.
Conclusion
Games should be considered art because it affects the human train of thought and it entertains.
Any medium of entertainment(even sex, for all you logicians) is art. Why? Because, it affects the senses, and it creates a reaction. If the Godfather movie gave you an idea of the harshness of a mobster's life, then Godfather the game gave you the chance to experience the idea.(although not as authentic and real, the intention to please is there)
Think of it like this, A movie, a novel, a painting is a finished piece of art. The only thing left to do is to savor the message, and produce a conclusion and reaction.
A video game is a finished piece of art but still needs input from the receiver before it can be given comprehension and understanding. Every game is like a canvass with predetermined figures already pre-drawn, but lacks color. What you need to do is to pick up the paint and apply it yourself. If you follow the trends and intentions of the developers correctly, you will finish the painting, get the message, and begin the comprehension process. Just like the other forms, of non interactive art...
my two cents...