Rama is a symbol of a person who accepts everything what his elders says( a good guy).On the contrary,Krishna teaches to kill even one's kith and kin if they are doing injustice to the society.
Krishna's teaching is not good for those people,who wants to rule the roost by befooling the people.Corrupt leaders and their associates wants to teach people about the good guy who can not revolt against their regime and accepts everything whether they are right or wrong.
This was the reason,our brahmanical system promoted Rama more than Lord Krishna.But people are getting awakened now and they are looking for the real value teaching,which they will learn from Krishna's life.
