I think in the second half of what you said you began to understand what you started out saying that you "don't understand." Think of "the consequence" here in

I think in the second half of what you said you began to understand what you started out saying that you "don't understand." Think of "the consequence" here in a purely security-theory way. In some sense that's what we're doing, securing ourselves from exploitation. Press and Dyson are expressing the radical idea that "if I protect myself from some stupid attackers, I protect myself from all smarter ones." How does this work? It works precisely because there is a threshold above which "smarter doesn't matter" -- a smarter attacker has the exact same payoffs as a stupid attacker playing a different strategy. In that sense there are no higher-order strategies for exploiting a sufficiently stupid strategy: sure you can program a smarter attack, but it cannot do better than a different, stupid attack. So if I intentionally choose my strategy to be stupid and show that, for all of your stupid strategies, the expected payoff is the same -- then for all of your smart strategies, the expected payoff is also the same! It's not quite "trying to predict randomness", it's "if I dumb myself down I can also assume, without loss of generality, that my adversaries are dumb."