Diagnostic
To clarify my rather hasty response - the point I am trying to make is that a change in the interface is not necessarily going to result in a future avoidance of this kind of accident. It is rather a measure which may well be useful but cannot take the place of training, CRM, using SOPs and a proper culture in the airline. If you recall the crew of AF447 ignored the stall warning - what guarantee do you have that they would have paid any attention to a UAS warning? The evidence of their actions suggests that it may well have been a waste of time. I referenced Korean Airlines. One of their accidents involved a captain ordering his co-pilot to tear out the stall warning klaxon because it was bothering him. The crew of AF447 ignored the stall warning. Now to touch on the point of the other accidents - all resulted in recovery and a return to normal flight. The outcome is the important thing here not necessarily the process. But even if a warning system is devised this is not a rapid process - it needs careful consideration and testing so that it can be properly deployed.
I understand that you would like to avoid the fact that this is a crew issue - I would too but one has to be honest and look at this issue dispassionately. It is possible that Air France have been developing a far too casual culture with respect to safety and this is more of a concern than the existence of a UAS system. There have been a number of worrying incidents of which AF447 was the worst which suggests that this is the case. I am also a little disturbed by your comments on 'knowing your machine' - it is imperative that a professional tries to know as much about his aircraft as he can. Not every detail but he at least knows how to use SOPs and does use them.