Easy Street:-
Airworthiness provision cannot alone deliver safe flying operations.
...and nobody here has suggested that it can,
AFAIK, but we have seen the tragic results of the lack of it in thread after thread in this forum.
From the moment that seat was placed in that aircraft there existed a potential for an airworthiness related accident to happen and sure enough it did, with fatal consequences.
Now we have the curious situation that a report into that accident has been issued by the UK Military Airworthiness Authority, aka the MAA, aka the MOD, and you say that:-
the report does not make airworthiness failings its focus
How very unsurprising!
Self Regulation Doesn't Work and in Aviation it Kills!