Like so many other former Qantas employees, Tony Webber was an intelligent person with some significant understanding of why Qantas had been a successful airline.
The current Qantas management could not afford someone who may dispute the path chosen by the Joyce/Clifford dictators.
I would argue there are no managers left at Qantas with previous experience at genuinely successful airlines (including Qantas when it was), as that is considered irrelevant to the current executive.