Moggiee I believe that you are in danger of confusing primary cause with the desire to seek blame (a normal human failing). The NTSB usually restricts their findings to the most probable cause, but in this instance there is more than one.
Few accidents have a sole cause; there are usually a collection of circumstances that when they come together the accident is inevitable. Many of the circumstances are beyond the apparent ‘probable cause’.
We do not know what guidance the management pilots provided to the Captain re training/assessment; was the Captain experienced in judging how far to let a First Officer progress, was he a fully 'qualified' trainer (experience of a training establishment), or was he ‘promoted’ to a training role (the NTSB concluded that the crew met the requirements – but are they good enough?).
Alternatively the Captain may have been providing every opportunity for the First Officer to succeed, enabling the benefit of a confidence boosting landing in difficult conditions (another human frailty of wishing to help others).
In hind sight, which always clarifies judgement, it may have been prudent for management to limit the First Officers flying to one aircraft type (active oversight required).
I don’t know of the extent of the differences between the DC10 and MD11, but the latter with FBW controls has some history of problems on approach and landing (the NTSB conclude that this was not a factor – how).
Then there could be the simulators, how accurate are they? Does simulator training provide adequate experience in the conditions of the accident, or is the time just used for the flight check - to get/keep a ‘ticket’.
The weather was not a factor (by itself), but in combination with the previous factors, the margins of safe flight could be eroded; then with just one further issue an incident or an accident results (if a bit more drift had been removed - or the gear had not broken, would it have been an accident?).
This accident, like many before it, follows the classic James Reason model of Active and Latent failures, and thus the need to defend in depth (Swiss Cheese model).