@Old Carthusian:
So far, though, the evidence/information points in the direction of the human factor not the aircraft.
Human factors are an integral part of aircraft design.
Manufacturers build an aircraft and then publish initial procedures according to how they believe it should be operated,
based on their design. These procedures are what pilots get in training. Later, based on operating experience, procedures and training can be modified. Recommendations for modification of stall recovery training have thus already been made by AB.
An aircraft which cannot be safely and efficiently operated by human pilots is deficient in human factors.