Is it? It's really not far fetched if you think about it. At a certain point in time computers become powerful enough to run complex simulations. Which is where we are headed with quantum computing. So if a civilization much more advanced than us reached this point 10,000 years before we did it's likely that our world would be a computing civilization they are running.
Think about it like this. Someone played the sims so long, that the sims themselves got to a technological level to create a game of sims themselves. Rinse, Wash, Repeat.