Crickey some very self-centred interests here. Australia is built on immigration it requires immigration and often they get
PR but never take up citizenship.
In some counties an expat partner gets work rights others not. Some need to offer work rights and other benefits like tax others not.
The decision on what is best for country will benefit some sectors and not others in the bigger picture the object is get the best outcome for country not a very small sub group of the country.
Now we from op we only have to go on 2 South Africans, no conformation they are 457 holders (Primary or Secondary) or maybe they are married to Australian citizens we don't know.
I do know I am a bit disappointed in self-centred interest from pilots that have about zero understanding of immigration and work rights laws of Australia, I assume with same position that my adopted kids should be kicked out of Private Education as soon as a Australian citizen wants a place at that school as the class is full - they have been here 2 years and 3-4 years until citizenship is possible.
I have no idea what is on the list, it was used as an example.