Mr. Koster and the Obvious

From Wired
For example, would-be mainstream games have to be much more accessible to the average player than the current crop, with less-complex interfaces and rules that ease players into the experience gradually. Further, Koster said, in an environment where many hard-core online players put in 40 or more hours a week, mainstream games would need to require a significantly smaller time investment.
“The games need to be something you can do casually, in an evening for an hour or less,” he said.
Gee, I wonder why no one ever thought of this before?