I feel that you are neglecting the first international airline to operate into CNS... PX.
They were offered the top billing on the first sign at the International Terminal when it first opened, but deferred to QF.
PX offered the first flights to USA and caused QF to operate out of CNS a good few years before they wanted to... and saved a good few hours of flying for passengers in the North Queensland area travelling to MNL, and HKG way before CX. "Why fly south to go north?"