I agree with you that there have not been great block buster games that I would consider tremendous works of art, but plenty of indy titles stir emotion and feel artistic. This is comparable to how movie block-busters like Iron Man that make millions are not very artistic, but smaller projects that often win the Oscars are.
The issue I see with gaming till now is not that games are made for profit, art and movies are still made for profit, it is that the barrier to entry was too high. To draw or shoot a movie or write a book you simply need paint or a camera or pen and paper respectively. I would put computer knowledge as a barrier as well, but that is a wash with the need for the talent needed to draw or write compelling stories. When it comes to games, people had to either settle for making simple games or they had to work for a studio that will impede their artistic vision for the sake of profit, understandably so since studios are businesses. Now more and more tools are being created to lower the barrier to entry, whether it is open source gaming engines or mobile markets like Android. As the barrier to entry for games continues to lower, their will be more and more games that approach art and it is a matter of time before a game arrives that is a piece of art.