It's disturbing to think that the pilots spent precious time trying to reboot the flight computers, rather than trying to stabilize the plane using the basic thrust, pitch, roll and yaw controls, maintaining level flight and an open throttle.

All automated controls like this should be tested with each input in turn (a) disabled and (b) actively malicious, followed by two inputs disabled / malicious, and perhaps three inputs disabled / malicious - with special attention paid to likely cascading failures. Anything the automated system can't deal with should (a) be detectable through sanity checks and (b) have a reliable human response that pilots are trained in.

My experience in flight is limited to some skydiving and flight simulators. What I know about stalling from lack of thrust in level flight is that the plane seems to pitch downwards and becomes relatively unresponsive to the small adjustments in the elevators that ought to correct this pitch. A stupidly simple feedback system that doesn't know about the impending stall would simply try to counteract the stall by pitching up further and further, until it ends up in a flat stall / spin. The problem being that stall warnings are based on wind speed, which in turn requires an instrument.