Whoever is behind that computer would really have to have computer opened all the time-to maintain existence of the universe, the computer should never be shut down for another 100 billion years-how exactly?
How much programming Programmer would need to put from the primordial forces, smallest sub-atomic particles, to the macro-world, you would need billions of years of universal evolution, than special programming of plants, animals and than humans?
How much much energy and programming you would really have to spend?
Not to mention universe is considered basically infinite, how do you program infinite universe with all the hyper-complexity?
If human brain is an simulation, than programmer would need put new hardware every single time brain decides something different?
Again, that's impossible.