Yes, some of this was out of JQ's hands but that doesn't excuse the appalling communication which Jetstar seems to excel at. You claim communication is not a priority; it should always be a priority. People can understand and cope with stuff-ups and delays. What they can't stand is being left in the dark. Once again, I feel sorry for the customer facing staff whilst management in Mascot and Melbourne hide behind their computers and either say nothing or management speak gobbledegook. Combining Jetstar's lack of competence in this area with both federal and NT public servants who feel the best way to advance a career is to do nothing was always going to be a balls-up.
You say Jetstar are limited in how they can respond because they are a LCC ignores the often advertised fact that they are part of the Qantas Group. AJ was proudly standing in front of a sign advertising both Qantas and Jetstar during last week's results announcement. QF can't disown them when it suits them and should step in to support, what are after all, their customers.
Joyce is the group CEO and de facto CEO of Qantas, so yes he should be standing in front of that sign. I'm not sure how Qantas is disowning them in this case?
Jetstar are a LCC and their ability to keep prices somewhat lower than a full service carrier is to keep their cost structure significantly lower. In different parts of the world LCCs have used different mechanisms to do this, but one almost universal strategy is to maximise aircraft utilisation. Keeping large numbers of spare aircraft around undermines this. If one has extraordinary scale you can have a little more latitude. A spare B788 for Jetstar is going to be 10% slack, whereas if you have 300 B737s, a spare aircraft is only 0.3% slack.
I've worked in an operations centre and when things are going wrong communicating with passengers is not the priority. As shocking as one may think, your priority is solving the problem. To do this, you're speaking to a huge number of people, crew on the aircraft, ground handling and customer facing ground staff at the outstation, maintenance at base and outstation, catering, speaking with your aircraft scheduling team, crew scheduling, meteorology, external partners like customs and immigration, ATC or slot allocators, flight dispatchers, etc. You're chasing down people, sometimes people are not responding, sometimes you don't even have direct access to people. Yet, you're coordinating all of this and things change minute to minute while simultaneously trying to manage the downstream/knock-on effects (e.g. taking a plane from another flight compromises planning for that flight and needs to be managed too).
You communicate plans to the crew on the aircraft and within minutes everything has changed. The plane you thought was available isn't, or maintenance need extra time on it, or it's being delayed by ATC elsewhere, or a drunk pax is needing to be offloaded first, or the crew that you had found for it now tells you they'll time out, or the crew you found on standby is stuck in traffic because there are roadworks on the highway, etc etc. So you're going to get critiqued for communicating poor information. The alternative is that you know that plans evolve quickly so you choose to not communicate until you have certainty, and now you're get critiqued for not communicating. Either way, you're getting pinged. All this while managing a bunch of other flights, e.g. you can't ignore a problem with that SYD-MEL flight you're managing since you're trying to avoid it missing its slot and its pax missing their connection.
But back to prioritisation: if I'm in the ops centre and speaking to the dispatchers to try and get an alternative aircraft an hour sooner than the previous one I've found, and trying to help them move things around to get this to happen, should I delay that call, or the multiple follow-up calls and tasks required to call the crew to update the passengers that I may have found an aircraft, but now I need to find crew and get them to the right place and arrange catering for that flight (because you'll beed to carry catering from base) and the million other things required? While I understand the need to communicate with passengers, solving the problem is the priority. The airline isn't intentionally providing poor information or not providing information.