QFi's problems are high costs relative to pretty much every other airline in the world - this is a geographic problem and very difficult to fix, albeit the position can be improved.
QFd's problems are high costs relative to other companies operating in the same industrial relations environment and in the same geographies - this is what can be fixed, or else they might as well shut down QFd mainline and just have the flights "Operated by Jetstar", much like the QFLink services.
QFd's issues started back with Compass - its just taken a while to work its way through the system