I reckon Bruce leaving just shows that he is actually a 'smart' businessman.
What he has done is drive down costs and in 'theory' created a profitable airline, he has 'record' staff engagement and has 'successfully' franchised the business across the globe. All of this has led to a big salary and a big bonus / profit sharing, he is going around gloating how good he has been, even Alan Joyce has told staff that he knows Bruce will be missed by ALL at Jetstar.
In reality, Jetstar Japan is just struggling by, Jetstar Hong Kong is rumoured to be dead in the water, the A330 AOC in Singapore is a non started and they have given up on this idea, Jetstar NZ services are being drastically cut and the operation is mainly being staffed by EBA pilots as no one wants to stay on the NZ contract, oh and lets not forget the massive expense of the failed Cadet experiment which has masterfully delivered really inexperienced pilots into the airline at double the cost of an experienced pilot
Thing is that all of these initiatives have delivered him massive pay and bonuses and by the time that they sink the ship he will be living it up large selling cosmetics from a market stall in Hong Kong with millions in the bank.