Ian W, that argument may have be made but in no way proven: you base your case on (rare) situations where the automatics have failed and pilots have failed to intervene correctly. Who knows how a fully automatic system would have responded Hardly convincing!
Similarly your earlier post spoke of being on board an aircraft in fully automatic operation. No you weren't. The autopilot was human programmed and under full human control as was every aspect of decision-making for the entire flight including failure cases.