If there wasn't a ridiculous peaked demand for services over about four hours per day, the railway would be much cheaper to run. Those who think that even after the infrastructure has been extended at great cost and rolling stock provisioned that spends most of the day in sidings waiting for the next peak run (singular in many cases), that their discounted fares*, subsidise those that use trains that would otherwise be empty, is a total misunderstanding of the transport business. The same issue was prevalenmt in BR days, (when I commuted) and has also been covered elsewhere or other world cities where peak demand is provided at great cost. I don't know hwether the self-interest arguments of the subsidised commuters are as prevalent as here though. In the US, there are some routes where there are only services in the peak, - at least we have the common sense to encourage use of expensively provisioned assets to try and reduce daytime road traffic.
* given that most of them are travelling on season tickets