My experiance comes from both sides of the fence, i worked at a large aerodrome where ASIC's are mandotory - no ASIC no access, no access - no pay, i'm currantly working my way through my PPL Nav-Ex's. Currant emploment (non flying) demands i have an Aust ASIC and they pay for it
However, i really believe that the new Federal Government seriously change the currant dogs breakfast that is ASIC. When the system was first mooted GA were to recieve grey backgrounds on their cards, this identified you as someone with a legal requirement to acess the GA apron only.
The red background was for the boys and girls who needed to be on the RPT apron. Simple really, do you really need an 'all access' card just to visit the GA apron to have a wizz and a cup of coffee? ( i do however inderstand at some smaller regional aerodromes that the RPT and GA aprons are one and the same)
I think the initial grey card would have satisfied any security concerns and may have been less exspensive for the GA community as (perhaps) the security checks would have been less expsansive. So the red card would distinguish the 'professionals' (with approiate costs) and the grey card the GA types, with again, an approiate cost.
Which ever group of no-hopers made the D to role both cards into one deserves a bullet!
Oh and the Grey card should be valid for 5 years and quite possiably be plastered on the back of your licence.