What made A bodies non-popular

the movie duel didnt help make the A body look cool. made it look like a working mans commuter with no power . now if they would have dropped a 340 in that lil red valiant and had barry newman drive it across country outrunning the cops, that would have made them cool cars. or picture that lil red valiant chasing down steve mcqueen through san fransisco. how about an orange valiant with an 01 on the door? other people besides us would be buying up A bodies left and right.