I can understand your point. But Butter biscuits you prefer but someone may not like it, chocolate /cream biscuits u may like but some other person may not like it OR maybe the other person is suffering from some disease like say diabetes so he/she may not prefer cream biscuits or chocolate biscuits. Senior citizens dont eat butter biscuits, cream biscuits, chocolate biscuits, etc. Railway cannot give different type of biscuits to different persons as per their choice in a say 16 to 18 coach Rajdhani/Duronto/Shatabdi/Gatiman Exp whatever u consider. It will be too costly for IR if they have to give different biscuits to different persons as per passenger demands. So, a common biscuit which almost all age group can eat i.e. Marie biscuit which older passengers can eat and other age groups can also eat is given in trains.
You...
more... cannot compare a bus with a train, bus has only say max 74 seats (correct me if i am wrong) whereas a train has 16 to 18 coaches and huge number of seats.