Qantas elites really only have access to good connections and lounges at DFW in North America, and while then can fly QF to JFK, the have to fly AA elsewhere which is a poor carrier even by American standards.
LAX is an AA hub, which arguably provides more than sufficient connectivity to major end destinations. In regards to AA being a poor carrier by American standards, to be honest, the legacies are much of a muchness.
In contrast, NZ elites have a better onward network and product not just at LAX but also at HNL and especially at SFO.
I suspect that HNL isn't the most important hub for elites, especially considering NZ only has 3pw service
NZ's SFO PM arrival time is also not the best for maximising connectivity.
Lastly, Qantas frequent flyers have no non-stop option from either MEL or BNE to get to SFO or YVR or HNL,
Neither do NZ Airpoints members
and the experience of flying Air NZ and connecting at AKL is far preferable to SYD.
I suspect many would argue that connecting to HNL via SYD is preferable to AKL, as one does not need to overnight in SYD, unlike AKL.
Like NZ flyers, QF flyers have one stop options via LAX from BNE to SFO and YVR. I'm not going to vouch for LAX being an awesome airport experience though!
Personally, I suspect given Australia-USA airfares are so cheap now since the entrance of DL & VA, NZ is less focused on feeder traffic from Australia, given the paltry yield.