Well said indeed Pobjoy. The fleets are grounded for airworthiness reasons, but you rightly list many of the failings that led to this. Predictable, predicted, notified and ignored.
I remain of the opinion the Air Cadet fleets are being singled out in an attempt to show MoD/MAA is being tough, to divert attention from the serious systemic failings affecting front line fleets and their support. The aircraft can be made fit for purpose. I doubt if the MoD/MAA can.