The real world is filled with industry know-how, real-life constraints, and monetary risk. I'm almost positive these people don't have millions of dollars lying around to invest in agriculture R&D.
Kind of like how the Travelling Salesman Problem is near impossible in a static network, it's truly impossible in real life as changing conditions constantly make the solution different, so even an instant answer isn't good enough.
I realize as I'm typing this that your thoughts are almost exactly what the more optimistic Communists thought in the Soviet Union (very laudatory towards you by the way), I really should get around to reading Red Plenty, I have a thing for bureaucratic tragedy.