Think you will find that it is very rare for a pilot to come into the cabin to sort out an agrevated problem as too many of us have been hit. (Not good trying to land plane with concussion even monitoring the other guy) My company frowns on that idea. Also we now have kevlar cockpit doors to ensure pilots are protected from undesirables. Flying the plane is the important bit off the ground. Gravity rules are hard. If my cabin crew were unable to "maintain good order and discipline on board" it is my job to ensure the safety of the aircraft. I would have been on the ground soonest letting the police sort it out.
As for engine starts giving problems or whatever that is NOT an engine failure!:o