What i have noted is that where there are no OBHK facility trains are cleaned at certain stations. until OBHK was there in RaptiSagar express the train was cleaned at ED when i used to travel from MAS to PGT. Well in your case it might be negligence from staff and a complaint should have been lodged and i am sure the cleaning staff at the next station would have done the job. You are also right as to why we should fight for basic amenities but on the other side i also feel that as a responsible citizen if we had complained the other pax would also have been benefited.