A system is only as good as its weakest link.
Currently that weakest link is airside staff that receive next to no screening. You can literally drive a truck through that hole.
Until this is fixed there is absolutely no point in beefing up security in other areas. The Australian article is spot on, although I wish the Tony Sheehans of this world would but out. He sees an opportunity to bolster union membership so his comments are clearly biased.
Either scan everyone heading airside to the same standard or just bin airport security completely and spend the money saved elsewhere on the intelligence gaining systems to spot the the problems before they get to an airport.