’Doing nothing or picking randomly are also choices, you would need a reason for them to be the correct rational choice. ‘Doing nothing’ in particular is the kind of thing we would design into an agent as a safe default, but ‘set all motors to 0’ is as much a choice as ‘set all motors to 1’. Doing at random is no more correct than doing each potential option sequentially.′
Doing nothing or picking randomly are no less rationally justified than acting by some arbitrary moral system. There is no rationally justifiable way that any rational being “should” act. You can’t rationally choose your utility function.