Pen-and-paper role-playing is live theater and computer games are television. People want the convenience and instant gratification of turning on the TV rather than getting dressed up and going out to see a live play. In the same way, the computer is a more immediately accessible way to play games.

As quoted in "Dungeon Masters in Cyberspace" in The New York Times (27 February 2006)

https://www.nytimes.com/2006/02/27/arts/dungeon-ma...