New Zealand and Australia are separate countries, they are no more "a country" than Canada and the US are. Happy to help yet again with your education.

If you look hard enough you'll find people who are against just about any law. The seatbelt in the back seat is not an issue in Australia, despite your best efforts to make it one - a handful of taxi drivers who make it into the paper as a bit of a novelty item doesn't make it so. The item that you quoted in the (snicker) Daily Telegraph didn't say how many drivers were involved in the protest, and only managed to find two for some rather lame quotes.

Go to a country and disobey the laws, just accept it and move on. The fact that you were ignorant is no defence, and I can't see any reason for the Kiwi cop to have used any discretion.