The problem being that as far as anyone at the time could see, the Maori, the Zulu, the Afghanis, the Nepalese etc. etc. etc. all appeared to have an organized and relatively sophisticated culture whereas the Australian aborigines were still living a hunter/gather lifestyle that was essentially proto-neolithic.
As far as could be seen, they had no larger organization above the clan group and certainly paid little interest to other aboriginal groups except for potential wives or as competitors for resources. They produced nothing extra to the basics of daily subsistence.
The aborigines were incredibly primitive compared to every other group the British had come in contact with and this lead to the state of affairs known as
Terra Nullius for Australia.
The fact that the aborigines had had no significant change in their culture or lifestyle for over 40,000 years meant they were ill-equipped to understand the concepts of warfare that the Maoris, the Zulu, the Nepalese and so on, so readily accepted. If the aborigines had been able to organize fighting units in a similar line with what the Maoris had, they probably would have been given similar status to the Maori. As it was, with the disdain Europeans had for the less cultured peoples of the world, the aborigines were seen as the most primitive of them all.