If I just happened to be a passenger on a pilot-less 777 whose engines died from iced fuel intakes on short finals into LHR, could I trust the Auto system to instantly put the nose down, accelerate, thus gaining enough lift and momentum to just clear the perimeter fence and put down on the grass without serious injuries?
Thought not!
It's a different matter with cargo planes and more acceptable because there would be no-one aboard at risk in a situation like that.
People on the ground beneath the freighter might see things differently!