I don't really buy the supply/demand argument everyone else is saying here. The end product just doesn't provide value to people's lives. The amount of effort you'd need to put in to provide value to someone's life through a video game is way higher than the effort you'd need to put into a productivity tool.
In fact, more often than not, video games provide negative value to people's lives. They're usually a waste of time at best. And at worst, addictive and carpal tunnel inducing.