People without a physical or legal presence in Australia likely don't care what the Australian law cares about.

I don't care about what Australia wants. If I ran a private Matrix instance (e.g. to chat with my gaming buddies) I wouldn't even agree to divulge who is registered on it.

I've been threatened by the governments of Pakistan and Germany for stuff I've said pseudonymously on the Internet. As much as they may think everybody needs to care about their laws, I happen not to.