At the risk of sounding a bit dramatic, I'm not sure this is an awful lot better than the spot betting fiasco that got the three Pakistani players imprisoned (specifically the moral emptiness of the two acts).
If you break it down, it's a calculated, premeditated attempt - by a number of senior staff and player to influence and alter the game using methods that have been deemed illegal - both before and during it. Ball tampering is one thing - Faf du Plessis has been done about 80 times for it, but this is different, it feels almost institutional and smacks of contempt for authority at a number of levels.
Everything I read and see about it makes me squirm. It's absolutely grim.
I wouldn't necessarily put it on the same level as spot fixing or even the larger match fixing scandal that Hansie got pinged for. Those acts showed complete contempt and disregard for the actual game and it's outcome, whereas this ball tampering is cheating in an attempt to gain an advantage on the field and would only benefit the Aussies if it came off. But we are talking about different shades of the same thing really.
I do agree with you on the strategic and planned aspect to it, which does make it so much worse than the dozens of other times players have been caught doing it. I also find the admission of guilt to be really disingenuous. Referring to a leadership group which consists of the best, and probably unsackable, players is just another tactic to get away with it without major repercussions. Saying the coach was not involved despite the footage showing clearly he knew what was up and the attempt to deceive the umpires was via his instructions.
If they had fully owned up to it and were more honest and open about it, I think people would be more forgiving. But they are still coming across as arrogant and above the rules and spirit of the game (which they conveniently throw into the faces of almost every opposition team when they get the chance).