Longer Ron
The technical investigation was carried out to an extremely high standard
I agree.
The wider airworthiness issues are separate to the technical investigation
I disagree, although see your point. Airworthiness is an engineering discipline and the engineer(s) on the SI panel should understand the impact systemic failings had on their findings. Duty of Care demands they report this.
I accept the SI's terms of reference do not seem to extend to underlying causes, so would place the onus on the MAA, who are seen to endorse and issue the report.
The aim is to prevent recurrence. As it stands, the SI's investigation and report may help prevent recurrence of that specific event at RAFAT, perhaps on Hawk. But most definitely NOT in the wider MoD.
That is because the root cause is, as you say, a wider malaise. There will be other avoidable accidents, and like many before them will be easily traced to the decision not to maintain build standards, safety cases or have a compliant RTS.
That this was a quite conscious DECISION in order to save money and hide waste, not an oversight or mistake, is what people cannot grasp, or in the case of MoD do not want to grasp.