> "I don’t think RocketLab had plans to ever commercially launch rockets out of NZ."

Not only do they have plans to, they have already launched multiple commercial missions on their Electron rocket from NZ!

> "Its latitude is really not optimal for anything other than polar orbits"

I don't think latitude is the major reason. Rocket Lab's Ahuriri Point launch site is at about 39.2 deg S, not that much different to the Wallops Island, Virginia site at 37.8 deg N. Baikonur Cosmodrome, by comparison, is at 46 deg N!

> "it’s too far from any potential customers which would increase the cost considerably."

Yeah, this is the real issue.