The answer is because New Zealand doesn't have the 2nd amendment, and a random bystander is a lot less likely to pull out a gun and shoot back.
Basically it's like asking why there are less traps in Saudia Arabia. If whipping out her salami could land her in prison or death, of course they're not going to show it off.
that doesn’t explain why shootings there have higher mortality - the mass shootings here are rarely resolved by second amendment gun carriers (ex: las vegas concert, college campus sniper). its that their police force isnt trained or equipped in dealing rapidly with a mass shooting event. for better or worse us law enforcement is really well prepared due to all the incidents here.
