DC-ATE:
Let's just list the "Probably Cause" now and save all this bandwidth of speculation.
The Probable Cause of the loss of AF447 was due to the aircraft having problems with the pitot static systems in an area of storms that caused the pilots to lose control of the aircraft because of erroneous airspeed and altitude indications, resulting in an upset from which they were unable to recover.
I would humbly rephrase it:
The Probable Cause of the loss of AF447 was due to the aircraft having problems with the pitot static systems,
the complete failure of all IR's and (maybe the partial) failure of the ISIS in an area of storms that caused the pilots to lose control of the aircraft because of erroneous
(or no) attitude, airspeed and altitude indications, resulting in an upset from which they were unable to recover.
(agree with you Safety Concerns, what disturbs me more is the failure of all IR's...)
V.