Well, it's just like how being homosexual was illegal in Australia but since so many people were being gay anyway, they decided to make it legal... so many people smoke weed in America these days that they have started de-criminalising it. It's a case of majority over law. People lose 'legal' pets all the time in Australia... What about when someone's pet reptile from northern queensland in the rainforest escapes out into somewhere into the dry areas of NSW? It is no different to someone losing their desexed Corn Snake out into their garden or pet chameleon out their window which manages to get out into the bushlands of Australia
Another point, Each exotic pet could be microchipped as well and if someone found someone's exotic pet out in the wild they would call some kind of wildlife service if they were smart and it can be returned to it's owner. If they took it to the vet or rang the RSPCA, the officer would notice it's an exotic animal straight away and send it to the corresponding authority for exotic wildlife where it can be returned to it's owner. There are currently quite alot of exotic species of reptiles kept in Australia as is... why not make some kind of compromise to making someone a criminal for keeping an animal they found out about as a kid or on the internet that they love so much they will break the law to keep it?
I just think Australia is a bit of a sour puss towards laws... No R Rated games allowed... No exotic animals... I think making them all one sex or desexing them first is a great compromise. It wouldn't have much of an effect on the environment anyway if done correctly...
FYI, i don't own any exotic animals... I may be in favour of them becoming legal, but they are still illegal in Australia.