After 25+ years of working in and out of Oz, the only times in those 25+ years that I have experienced TIBA was as a passenger flying in and out of Australia.
Just imagine it if you will...flying from third world sh!tholes, through third world countries like the Middle East, India, Pakistan, Sri Lanka etc etc all at standard levels and given an ATC service (please no bitching about the quality of that service, at least they were there!) you arrive in the much vaunted "world's best practice" airspace to climb or descend 500 feet and then the poor old drivers up the front are calling and listening and warming up the mark one eyeballs!!! An ABSOLUTE national disgrace! I am shocked (but not really surprised) that Civilair don't make a bit of political capital by embarrassing senior management. I mean FFS, if they can't get this heard at the highest levels, why are they there?
A friend of mine asked me once if I thought it was a bit medodramatic to say that it was dangerous not having controllers when there was TCAS in all the aircraft.
I gave my opinion that it was actually worse than he thought.
What happens with an emergency I asked? At least if there is an ATCO listening, he can alert the appropriate authorities, and someone will actually get the fire fighters out and ready rather than the old saying that in a vaccuum no one can hear you scream.
In TIBA, you had better hope that someone relays your mayday call.....