I’m not sure anyone is suggesting to shut down JQ. That genie is out of the bottle. It does seem pretty pointless though to be launching a 737 and an A320 between SYD and MEL at the same time.
There was a time pre JQ when QF was making bloody good money with a full 767 every half hour or so between SYD- MEL- SYD and SYD- BNE- SYD. Over the subsequent 15 years that could have expanded to an A333. Instead we now launch a 737 and an A320 along with the duplicated back of house structures. Doesn’t seem all that efficient to me when you could have simply quarantined the back half of an A330 and declared it a ‘pay for stuff as you go’ zone.