Why do they have such a problem doing the same in some cases?
Simple answer. It stems right from the time these pilots do their first session in an airline simulator where the total accent is on using the automatic pilot and associated AFDS. Watch most simulator sessions. One of the first actions is to turn on the flight director. It is a good bet the vast majority of pilots first actions after raising the landing gear after take off is to engage the automatics. They were taught in the simulator this is the way to fly an airliner. Same with approach and landing. The last action before touch-down is to dis-engage the automatic pilot.
The above may sound like too much of a generalisation. But it is very close to the truth. This inevitably leads to the situation where hand flying is avoided like the plague. The Boeing 777 Asian crash at SFO is the tip of the iceberg. As a Boeing test pilot once told a colleague about the 787 design. He said "The Boeing 787 was designed on the basis it will be flown by incompetent pilots. Hence the numerous automatic protection systems in place".