RVDT,
You are quite correct - there is no way we can prevent this accident.
However, each accident should be seen as an opportunity to reconsider the way we operate and learn relevant lessons. My view is/was that, in spite of the aircraft being equipped for flight following, there didn't appear to be a system in place to make best use of the equipment.
Clearly, and as seen from the Australian quote, systems are available to provide a warning whenever the signal is not transmitted. This need not be a closely monitored system (although that would be preferable), it could be an automated system that notifies - by text and email - the responsible person/authority.
Without a human in the loop, such monitoring systems are merely eye-candy.