It's called lobbying effect. Once a convention gets spotlight it's hard to switch to new efficient when available. This has been a core nature in our national culture.
Railways being a government laid-back-work-culture body, comes up with enormous excuses to label better efficacies as not feasible. Similar multiple cases do exist. For eg. RNC/PRR - HWH doesn't have a single train on the shortest path even though it's very feasible.