Irrespective on how much damage a particular species has actually caused or has the potential to cause, exotic reptiles and amphibians have no place in Australia. There's no telling what kind of impact a species can have on Australia's ecosystems until it has escaped and established itself. It's not just the animal, but the diseases it may be carrying. I'm thinking of chytrid fungus. Prevention is better than cure. I'm saying this as a person who loves and admires exotics. In a perfect world where exotics were clear of diseases and there was no way of them escaping into the wild, then I don't see the problem. I would probably keep a few exotics in a heartbeat. But can we trust people to contain their animals, or worse, trust them not to release their animals into the wild when they no longer wanted to keep them? I've been to islands, some of a decent size such as Rottnest, some just a tiny spit of land, where there were no exotics of any kind. I can't describe it, but it's something remarkable being able to visit a pristine ecosystem that has not been decimated by introduced vermin. Do we really want to risk what still remains?