Perhaps you're right, and as you point out we do this with computers now. However the difference is these computers do not hold a complexity that is near infinite. Which is what it would require to create a simulation that included consciousness and quantum mechanics.
In my humble opinion, the thought of a computer that can work out each position of each atom in such a vast space in realtime, yet not be able to solve equations that were generated by its own generations, is not a plausible one.