Qantas started the NZ domestic flights as a feeder service for its international operations so why would they convert it to a LCC operation which obviously could not act as a feeder.
The issue is that Wellington is a jewel in the Trans Tasman crown, but 20% of international pax at WLG are business pax and 50% of domestic pax to WLG are business travellers who demand a higher level of in flight service, refreshment etc.
Pacific Blue when they first attacked the WLG-SYD route couldn't attract business travelers and had to abandon the route.
WLG-BNE on the other hand is entirely a leisure market and quite suited to Jetstar.
Jetconnect could not offer the frequency to make WLG-CHC viable.
Truth is that ROT-CHC is also probably a leisure route. Some Jetconnect routes would be more viable as Jetstar cattle class, whilst the WLG routes wouldn't be.