If these exemptions are going to be pulled, the SAAA/RAA etc. might have something to say.
Buckshot,
Not quite certain what SAAA "exemptions" you are talking about, as far as equipment and pilot qualifications are concerned, (SAAA is not a self administrative body) and a power source, normal GA rules apply to VH- Experimental and the like.
As for RAOz, if the aircraft has the equipment and the pilot has a current PPL, normal GA rules apply. The number of powered aircraft that do not have a power source is tiny.
I am not certain where the program is at, but for years RAOz has been negotiating with CASA for a "Controlled Airspace" training module for Pilot Certificate holders, so, with that in place, there will be no need for "general" exemptions for RAOz.
There are one of more localities, where special procedures have been put in place for RAOz aircraft, Cambridge comes to mind, but that is a different issue, and the problem will go away with CTL Airspace rights attached to an RAOz Pilot Certificate.
The glider "exemption" is a different issue, as they do not have the power supply to run a conventional transponder, carrying enough batteries for a long flight would be weight prohibitive. In any event, multiple separation assurance studies, over many years, shows that the likelihood of a collision between a glider and a powered aircraft is vanishingly small. Hangliders likewise do not have a power source for a transponder.
The immediately above comment actually applies to all aircraft, once you get away from the circuit area of an airfield, the place (obviously --- but not obvious to some) where a collision is most likely.
The Australian requirement for a Mode C transponder in E below 10,000 never had anything to do with collision risk probability, and risk reduction.
It was a sop to those vehemently opposing the introduction of Class E airspace. At the time, it was believed that the majority of aircraft likely to operate in E above 8500 would already have a Mode C transponder, so the compliance cost of making such mandatory in E was minimal.
The one obsession for which there has so far been no cure is the Australian obsession for "fly-by mouth", once your lips stop flapping, the aeroplane quits flying.
Keep your eyes out the window, folks.
Tootle pip!!