I would suggest to you that once Australian ATC's work under the same liability laws that exist in the U.S. they wouldn't give a fat rats arse about working Class E airspace. Their union is doing the responsible thing by their members, the only thing they can do. Defend their members from the liability they face with this airspace.
I read an article in U.S. Flying, a pilot got into icing trouble and ended up below LSALT, indeed, in a valley below the terrain. The ATC was able to give the aircraft vectors to keep him in the valley away from the mountains on either side. Would NEVER happen in Australia, the ATC would get sued.