Lyman, I'd like to revisit a fundamental task drilled into pilots from formative days, formative hours. This is in reference to the "mayday call" idea and what raises or lowers the nose.
The fundamental? Aviate. Navigate. Communicate. Given the trouble with the first, any pretense that the last -- calling Mayday or whatever -- has any importance is incorrect.
Aviate.
Pilots are (or should) control the aircraft. If it does X, and X isn't what should be happening, the pilot, using the systems at his disposal, makes it do something else. That is the premise of "controlled flight" versus "uncontrolled flight" or even "passenger in the very front seat."
While the THS certainly helps find a pitch attitude commanded by the system, there is a certain monotony to repeating again and again that the pilots inputs are part of the system. Based on what the FDR data found, the input from the SS was not cut out leaving the pilot at the mercy of the robot.
Why the pilot at the controls kept the nose up is in part (in my mind) explained by the idea that he latched onto the FD as a primary scan item, rather than flying a more primative scan based upon attitude indicator (artificial horizon if you like) compared to other instruments, which takes us back to opinions rendered here on PPRuNe while the BEA were still trying to find the wreckage site deep in the Atlantic Ocean: the Pitch and Power chorus will once again seranade us, since pitch and power comprise fundamental concerns of the fundamental number 1 noted above.
Aviate. Why that broke down seems to have a far heavier HF component (culture, training, and more) than mechanical component, though the complaints on how nuanced the control laws can become in the variety of degraded modes seems to have some merit.