The secret is not all that secret really.
Don't piss off your loyal customers.
Don't pass off your loyal staff.
Don't piss off your loyal retired staff willing to travel.
All these folk prefer flying with someone else now.
If I see it, as a business traveller, and I see high yield first class customers feeling the same way, surely there are large numbers of revenue dollars leaking uncontrollably.
The only way we go back is when there is no better option.
The board can complain about anything else all day. But to make a change they need to focus on doing the things that make customers loyal, and don't mind paying. Qantas has taught it's customers to object to paying for a quality product and subsequently not having one to offer.