The problem... one of the problems is that, say, you force every Year 12 student to learn Indonesian, a clear majority of those students will not be able to use their new knowledge of Indonesian in the Australian streets, and most Australians that do travel to Bali, or Jakarta expect the locals to learn English, not the other way around.
There also has not been a history of multilingualism here in Australia, beginning with the early settlers. Compare that with Canadians or Belgians, etc.