Of course, hindsight is always 20/20. As I understand it, at the time JQ longhaul was being dreamed up, the A332s were the orphans in the fleet because the longer turnarounds were causing some issues on the domestic operation. At that time they preferred the 763s for additional lift, while there was little incentive to add too many widebodies to the transcon services. And they were going to be replaced soon after with the 788s, allowing the A332s to come back to QF. Of course, the 788s were delayed by years, Virgin got widebodies for the transons and the market changed in a way that QF/JQ did not see coming, or if they did they moved too late to address it.
Hopefully now with the A332s going back to QF and getting new interiors they will move across to the international arm and start right-sizing some of their markets.