Emergencies are very often situations in which the plane is operating outside of normal parameters or even outside of specified parameters, e.g. a sensor failure or damage to the aircraft. In those situations software can not reliably control the plane and should return control to the crew.

The nature of emergencies themselve make dealing with them in software near impossible. How do you write software for a condition you can not anticipate? How would you test it? How can you make sure that it is not misdiagnosing a situation and making the problem worse?

The 737max disaster should be enough to demonstrate how dangerous misbehaving software in a plane can be.