This practice is not slimy by the airline because everyone is getting exactly what they paid for. The passengers to Melbourne are getting a flight to Melbourne

This practice is not slimy by the airline because everyone is getting exactly what they paid for. The passengers to Melbourne are getting a flight to Melbourne. The passengers to Adelaide are getting a flight to Adelaide. The government is getting the industry protection from international competition that it wanted by banning the airlines from selling flights from Melbourne to Adelaide to fill the seats. The airline wants to minimize empty seats and the government wants to allow domestic airlines to extract excess profit by protecting domestic airlines from competition but DGAF about empty seats. Therefore it is the governments fault that there are empty seats.