That's because its not a ban, it was a customs issue that one retailer was having because their imports were being sent back since they lacked the classification. A comment I found on r/worldnews explains it quite well:
*"OK this article is somewhat bullshit. Firstly, there hasn't been any recent change in the law, and this article is thus based purely on the fact that some packages being sent by one particular company (J-List) were getting rejected, and so rather than trying to figure out exactly what is and isn't allowed, they are just going to stop mailing all adult content.
Secondly, this is not really an issue of 'censorship' or Australia being unusually puritan about adult content. It's important to note here that this is an issue of customs law, not laws relating to the legality of the content itself. Most of this stuff would be perfectly legal to own in Australia. But unless it has been classified by the OFLC, it won't be legal to import as an individual. Or to put it another way, there's a mis-alignment between customs law (what you can import as an individual) and content/classification laws (what's actually legal to own or sell in Australia). This is partly because customs laws are Federal, but what you can and can't legally own is largely the domain of the States.
After all, there are plenty of adult stores in Australia selling porn and toys and what have you, no different in their content to the JAV DVDs and toys that J-List are calling "banned". But those stores are Australian-registered companies who have the appropriate importation permits, and the content itself has been classified as required by law. That's the difference. It's the same reason why you as an individual can't import 1000 cartons of cigarettes, but a supermarket chain can. Australia has notoriously strict customs.
If you set up a company to import JAV content and had the proper paperwork and classifications performed, most of it would be legal in Australia (obviously not child porn or bestiality etc. though).
I should also point out that in all states except WA and NT, it is perfectly legal to own even non-classified/refused classification content. It's merely illegal to sell it. That's an important distinction."*