Considering most Oz airports are not security controled airports - what is it that ASICs are supposed to acheive.
Passengers boarding either comercial or private flights do not need ASICs.
As has been pointed out, the people tasked to do the checking of ASICs at many airports are well known. Not hard for osama the bad guy to work out when best to enter the airport.
The costs of having a representative of the airport do the card checking is added to the airport running costs - higher landing fees and ground rental costs.