"#MetService is New Zealand's national weather authority and the Government-approved sole provider of severe weather warnings.

.. a State Owned Enterprise established to deliver weather services to benefit New Zealand's people and economy."

https://about.metservice.com/our-company/about-us/

So, if the public of Aotearoa own MetService, why is the software and weather data they produce proprietary? Remember this is totally compatible with being a social enterprise charging fees for services etc, rather than "IP" rents.