Today's NZ Herald editorial has made the point that is ignored by the anti rail privatisation church:
"If those private owners who put their money into the assets did not maintain their investment, there must have been a reason. They would surely have not let those assets deteriorate if rail was truly competitive with road transport and capable of realising a good profit. Passenger services would not have ended if people had viewed trains as a preferred means of transport. Most recently, Toll had been unable to make the business afford the rent that the Treasury wanted for use of the Crown-owned track network. Clearly, there was a significant distance between the profitability of the rail service and the cost of infrastructure maintenance."
Absolutely furthermore "People will also take some convincing that modernisation, in itself, will make rail attractive to customers. Evidence supplied by Wisconsin Central and Toll suggests there is a substantial, perhaps unbridgeable, gap between it and roading in purely economic terms."
So you see, it was economically rational to run down the railway system. It simply wasn't worth it. Unless of course you believe the nonsense about the environment, or you want a train set to run.