You really cannot blame the crew.
They experienced (i.e. quietly slipped into) a pitch-up (and thrust-) induced, and very insidious, deep-stall entry at high altitude - a straight unapparent and unremarkable entry into a very high descent rate, featuring a quite misleading and almost normal pitch attitude.
It's a bizarre phenomenon that's unique to the environment and only possible due to automation (especially the auto-trimming of the horizontal stabilizer) – but perhaps also due to the pitch-up effect of applying full power to underslung wing-mounted engines…... an Air France SOP (as with many other airlines).
In the deep stall:
a. the stall warning trigger threshold "cooks off" at a LOWER AoA and remains silent at deep-stall AoA's (i.e. any attempt to stick fwd [and thus lower the nose] triggers a quite deterrent aural stall warning – so any prudent pilot unstalling actions are thwarted).
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b. All the normal audible and airframe vibrational cues of a stall are absent (i.e. wing-induced turbulence does not impinge upon the tail surfaces) - so the ensuing stalled flight condition is quite uncharacteristically "smooth" (for a stalled state).
c. prior training is irrelevant to the point of being misleading (including the aural exhortations to "Pull UP")
d. time is simply not available to resolve what's happening, particularly against a background cacophony of aural alarms and visual alerts.
e. auto-rotational wing-drop trends are "managed" by the flight control system - so there is no "give the game away" tendency towards spin entry. Once any bank component becomes part of the attitude presentation, a pilot may be inspired to take an Unusual Attitude (i.e. “upset”) recovery action. However in this case the bank remained well within limits and the pitch attitude was around what one would expect. One tends to think of that soubriquet “sucked in” when considering the AF crew’s dilemma once in deep-stall territory, i.e. a propos automation “set-ups” and confidence tricks.
f. pilot sidestick inputs are always hidden from the other pilot and any unseated observer
g. engine thrust increases tend to induce (or sustain) the pitch-up into the high AoA stall attitude (around 40 degrees AoA) and helps "mask" the stall by approximating a level flight attitude.
h. disbelief is the thief of time
It is just one of the "late to the party" Achilles Heels of automation.
THE FINAL MOMENTS
Marc Dubois (captain): 'Get your wings horizontal.'
David Robert (pilot): 'Level your wings.'
Pierre-Cedric Bonin (pilot): 'That's what I'm trying to do... What the... how is it we are going down like this?'
Robert: 'See what you can do with the commands up there, the primaries and so on…Climb climb, climb, climb.'
Bonin: 'But I have been pulling back on the stick all the way for a while.'
Dubois: 'No, no, no, don't climb.'
Robert: 'Ok give me control, give me control.'
Dubois: 'Watch out you are pulling up.'
Robert: 'Am I?'
Bonin: 'Well you should, we are at 4,000.'
As they approach the water, the on-board computer is heard to announce: 'Sink rate. Pull up, pull up, pull up.'
To which Captain Dubois reacts with the words: 'Go on: pull.'
Bonin: 'We're pulling, pulling, pulling, pulling.'
The crew never discuss the possibility that they are about to crash, instead concentrating on trying to right the plane throughout the final four minutes.
Dubois: 'Ten degrees pitch.'
Robert: 'Go back up!…Go back up!…Go back up!… Go back up!'
Bonin: 'But I’ve been going down at maximum level for a while.'
Dubois: 'No, No, No!… Don’t go up !… No, No!'
Bonin: 'Go down, then!' (a poorly expressed exhortation to lower the nose?)
Robert: 'Damn it! We’re going to crash. It can’t be true!'
Bonin: 'But what’s happening?!'
The recording stops.
Read more: 'Damn it, we're going to crash, it can't be true!': Terrified final words of pilot on doomed Air France jet | Mail Online