Why not? QF and VA would kill them with capacity - just like QF did to VA for years. They have no lounge network in Aus to take corporate travel (and space can be hard to get). And despite any dubious “brand reports” to the contrary the majority of Australians like flying Qantas and wouldn’t touch AirNZ with a barge pole. Aussies have the same Stockholm syndorme to QF that kiwis have to NZ.

And who would they be? Jetstar and Tiger do a better job at discount flying, QF do better full service and VA are the closest to them but they still offer business class on all mainline domestic routes.

Also Airpoints is possibly the most horrible program in the world and not even remotely close to the same value as Velocity or QF FF - so that would need to be reviewed as well.

Im sure there are also other reasons as well - but that’s my rookie take.