The potential was there in the AoA value, but the aircraft refused to deliver up to alpha max ...
CONF iture,
Why did the aircraft fail to deliver
up to alpha max ??
It didn't because it would have stalled!
That's the NTSB's take on it in their
Final Report page 97, 2.7.2 High-AOA Envelope Limitations;
The airplane’s airspeed in the last 150 feet of the descent was low enough to activate the alpha-protection mode of the airplane’s fly-by-wire envelope protection features. The captain progressively pulled aft on the sidestick as the airplane descended below 100 feet, and he pulled the sidestick to its aft stop in the last 50 feet, indicating that he was attempting to raise the airplane nose to flare and soften the touchdown on the water. The A320 alpha-protection mode incorporates features that can attenuate pilot sidestick pitch inputs. Because of these features, the airplane could not reach the maximum AOA attainable in pitch normal law for the airplane weight and configuration; however, the airplane did provide maximum performance for the weight and configuration at that time.
.... The flight envelope protections allowed the captain to pull full aft on the sidestick without the risk of stalling the airplane.
They say that the alpha protections
prevented any further NU.