Just read the NTSB report on Flight 1549, very interesting, thanks for the link!
mm43:
There is a AoA threshold from the activation of the alpha protection to the maximum flyable AoA (p. 11). So in a sense, the aircraft did failed to attain the maximum alpha.
Here is one point (p. 96) from the difficulties mentioned by the NTSB report on ditching the Bus:
• Deliberately or inadvertently slowing the airplane into the alpha-protection mode may result in an attenuation of pilot nose-up stick inputs, making it more difficult to flare the airplane, even if AOA margin to alpha maximum exist
!
"They say that the alpha protections prevented any further NU."
Exactly. And it is NOT necessarily a good thing in this case.
And I firmly believe that the Captain (even if he didn't kept up the airspeed quite correctly), would have not pulled the stick like a mindless monkey if there weren't any protection.
I believe he would have stalled the airplane just a few inches above the water
