Everyone knows that the provision of ADS-B over the remote area above FL290 was mainly ego driven, so Airservices could tell the world that they had covered Australia. Of course, the risk there was non-existent. With so little traffic, everyone on full position reporting operating IFR under a clearance, and the best TCAS equipment, there was simply an imperceptibly small chance of a mid-air.
Dick you are making up "facts" here to support a bad argument. The remote areas you mention are overflown by numerous aircraft above FL290. Just about everything to and from Asia goes this way. A look at Plane Finder a short time ago sowed around fifty aircraft there and that's in a quiet time. ADS-B which gives on screen surveillance has allowed separation to be reduced from the large time and distance standards to five miles. Add RVSM and flexible tracking to this and there have been large savings in distance, time and fuel. When I was in Alice Tower in the 80s, the enroute controlled in AS TWR controlled 200nm radius up to FL400. With the improved surveillance and communication, Alice now has a Class D tower 15 DME radius up to 4500.
You say that ADS-B should be used by Class D tower controllers. This was covered in your Tasmanian posts. Take Broome. There is a single ADS-B station there. One is not enough to guarantee surveillance if it fails. At high level, there is more coverage. Who would foot the bill th install extra stations n the Broome area? A similar situation exists in Hobart. The five versus three mile separation was also explained. The processors for the Tasmanian ADS-B sites are in Melbourne. This causes latency problems if trying to use three miles in the HB TMA.
You have often said that you are attacking the system and not the controllers but you have included the following:
That is, industrial resistance to change by the air traffic controllers...