If the Rail Industry was to offer the service you have in mind, always offering the cheapest method of travelling from A to B, then certainly revenue would be diminished. Meanwhile, costs will remain unchanged.
I imagine it is possible that costs may even increase to provide this service. Presumably it would require some sort of IT investment?
Alternatively, if they had to provide the service using the current system of searching, then surely more manpower would be needed to keep the queues down after Joe Bloggs has requested possible splits at 19 stations.