While, personally, I don't see a rolling gauge conversion of the entire state network as being impossible. In fact, perhaps even practical. There is far too many other disruptive factors (namely - it's not politically worthwhile, and would be a real pain in the rear end for commuters going to Inner Melbourne while lines are being converted).
The fact that we have a pretty bad history of taking forever to actually start and complete projects doesn't help.
Either way, that being said, I don't quite think Myrtone
has a very good grasp of reality.
In addition, Victoria's biggest problems, that I understand, regarding freight, are that there's simply no freight operators that either care, or have any real resources.
While regauging would allow desperately needed competition to come into this state, with much more modern and numerous Standard Gauge rollingstock (the lack of Broad Gauge rollingstock being a serious dampener for running freight locally), the simple fact that the Government hasn't done anything, I dare say, "serious" to try and encourage running rail freight as intensely as Queensland or New South Wales is a significant contributor to our problems. Regardless of what Rail Gauge is being used.
This, in itself, does not really discuss the Passenger Network. But, I have an appointment to run to, and I really don't want to get into that.
As others have stated, the topic has been beaten to death. The horse is not just dead, it's rotted away, its flesh gone, and the bones turned to dust. We're not just beating the dead horse, we're beating the ground hard enough and for long enough to create a crater rivaling those from the Moon.