The difference is that humans are not like control systems, they are control systems, and are not and cannot be modelled as sets of "if-then" loops, whatever those are supposed to be.

Er, isn't that the "program" level of Powers's model? IOW, his model shows how you can build up from more fundamental control structures to get complex "programs". See chapters 13-18 of Behavior: The Control Of Perception. (At least in the 2nd edition, which is all I've read.)