I believe you are correct in that IIRC 100 points of ID should be required...
Pragmatically it is not enforced by many many outlets. I've purchased $20/$30 starter packs with SIMs at: Coles, Servos, and even paid cash at the Telstra shop at SYD airport T3 last year without any form of ID. You can find them on ebay.com.au and pay with a prepaid credit card.
Just guessing that not too many people care since it hasn't presented a major security risk so far.
Also on that whirlpool.net.au website you'll find many people who also have purchased SIMs without ID.