To play Devil's Advocate....
Irrespective of what you think of cadets, industry placement and experience is something that most of us have been calling for for some time - albeit for various reasons.
I can see the argument that these individuals "entry" into Qantas has been "delayed" by two years or whatever it takes to do their industry placement. Therefore there is an argument for giving them seniority numbers when their cadet course is complete not when they enter the airline.
I can also see that this will p%^s off a lot of people.
