There are some recurring pointless posts and themes now obscuring this tragic thread. Before refusing to believe anything or putting on rose tinted glasses, I suggest everyone review one of the very few truly enlightening and sensible posts on here, which was from Capt Kremin, who basically called this very early on logical grounds as per known facts. I do not know how to link his posts so reproduce one here, which if you are prepared to consider facts from an experienced Airbus pilot, is worth its weight in gold:
The bewilderment of the Lufthansa CEO regarding this incident is telling.
There has been no mention of any faults being revealed via ACARS. If you cut back to AF447 they were referenced very early in the piece.
The Lufthansa CEO would be apprised very early by his own people if any hint of mechanical problems was evident. But nothing so far except extreme bewilderment.
The aircraft was travelling at excessive speed; in excess of VMO. That is acceptable if you are on fire and heading for Nice or somewhere like that. This aircraft remained on track.
Travelling in excess of VMO in a A320 disconnects the AP and triggers the high speed protections which pitch the aircraft up. This aircraft did not pitch up. Which probably means it was being over-ridden by whomever was flying it.
That raises the possibility that the aircraft was hand flown all the way down.
That is ok if you are trying to get to an airport quickly but this aircraft stayed on track and headed directly for the Alps.
This aircraft did not capture any altitudes. Either the descent altitude was set below 6000 feet on the FCU; unlikely but it could have been done in error for the initial descent, or it was being hand flown.
Pulling open des on an emergency descent, provided a lower altitude is set in the FCU, in cruise engages the speed mode which would have captured the cruise mach, which then would have crossed-over to an IAS somewhere on descent. The autothrust commands IDLE and the selected speed is controlled by the elevators.
Therefore only way to achieve max speed is if someone sets it there. There is no reason to do so, and you certainly don't deliberately fly in excess of VMO. The high speed protections would be fighting against you.
Barring some sort of irrecoverable autoflight glitch, the foul play aspect will be increasingly looked at.