EMIT;
One factor that is definitively causal and that I keep missing in the shortlists of causal factors is the fact that all accident approaches were carried out with AutoThrust engaged untill touchdown.
Couple of items...
1. Re, "until touchdown"...do you mean just before touchdown or really "right until touchdown"? I ask because the Airbus SOP requires that the thrust levers (both) be reduced to IDLE by 20ft, (10ft on an autoland). Some long landings are caused by keeping the TL's in the CLB detent until touchdown among other inappropriate events.
2. I don't think you can use the words 'causal factor' when referring to the fact that autothrust was engaged 'at' touchdown on 'all accident approaches'. That might be close (though not exactly!) like saying the Nav lights were 'on' on 'all accident approaches'. The fact that the autothrust was on, on all accident approaches, cannot be cited as a primary 'cause' the accident.
But I think I know what you are saying - that there may be a relationship between the autothrust being on and the PF not being "engaged" or cognizant of the lever positions (and engine power being developed) in the same way that flying a manual thrust approach provides the PF.
This homes in on one Airbus controversy which many who otherwise love flying this type have commented on - that "manual flight", or "keeping one's hand in", is and remains a high priority for pilots.
Presently, our manual prohibits the use of manual thrust except in extraordinary circumstances such as a clear intent to "practice" in a benign ATC/operational environment. Many believe this to be a fundamental mistake and have fought such prohibition for years. We finally lost. Now, one disconnects the autothrust at one's peril should anything happen. Many crews used to fly approaches manually, including manual thrust levers, all the time and I personally taught it in instructional situations and encouraged it in regular line flying. No longer; the "risk" of blame is too high. In my view, competency with the machine is thereby lost however and, with such AOM restrictions, the relative loss of competency becomes self-fulfilling problem or a vicious circle. It is a big issue, as you likely know.
PJ2