Someone should tell him indie developer Bay 12 Games has already done that. Dwarf Fortress is a single-player ASCII-based title that's a a cross between a roguelike and a real time strategy game. It's definitely no movie set, but the level of interactivity in the game's persistent world is monumental.
To give you an idea how massive Dwarf Fortress is, generating the initial world can take fifteen minutes or more. Think about that. An ASCII game on today's processors working for fifteen minutes. Every landmark above and below ground is named, thousands of creatures living persistent lives populate the environment, there's a bustling economy, weather effects, seasons, and a complete world history. All of which you can interact with.
Do developers spend too much time finding new ways for technology to play with itself rather than focusing on the end experience? It's a tired old debate, but Dwarf Fortress is proof the concept of gaming can evolve independent of the technology used to present it.