I can see the point from an aerodrome security point of view, but insisting on security checks for GA pilots is just another double standard, seeing as RA-Aus people don't have to have any kind of security check.
I think this is what should be focussed on rather than ranting about the cost etc, so talk to your local Senator about Section 6.55 of the Aviation Transport Security Regulations 2005 as this is to do with OTS not CASA.