Just a minor thought connected with the orthogonality thesis: if you claim that any superintelligence will inevitably converge to some true code of morality, then you are also claiming that no measures can be taken by its creators to prevent this convergence. In other words, the superintelligence will be uncontrollable.
Nothing mysterious here: this naive approach has incredibly low payoff per computation, and even if you start with such system, and get it to be smart enough to make improvements, the first thing it'll be improving is changing it's architecture.
If I gave you 10^40 flops, which probably can support 'super intelligent' mind, your naive approach would still be dumber than a housecat on many tasks. For some world evolution & utility, you can do inverse of the 'simulate and choose' much better (think towering exponents times better) than brute-force 'try different actions'. In general you can't. Some functions are easier to find inverse of, than others. A lot easier.