You are assuming the authorities have common sense, and that they base their decisions on logic, and with help from those in the know, people involved with the industry/hobby etc.
Instead of encouraging people to look after and breed native animals like gecko's, they put up barriers and make it difficult. Imagine if tuatara were being kept and bred to the same extent as bearded dragons, perhaps with a percentage of offspring being released into reserves.
Instead they happily let people keep animals like red eared sliders, that are capible of living outside in warmer areas and actually have a chance at becoming an established pest, but they ban animals like amazon stingrays that are hard enough to keep alive in captivity, let alone in a cold muddy river in NZ.
There are plenty of people who keep animals like gecko's without permits, simply because they can't be bothered with all the red tape and bureaucracy. I hate to think what would happen to the animals (and the responsible owners who look after them well) if they were found out by the authorities, common sense would play no part and we'd end up in a situation where the animals would probably be destroyed and the owner prosecuted for breeding and increasing an endangered species. :roll:
If you don't mind me asking, why such an interest in our laws? Are you planning on moving here some time?