Now an obvious friction between the Brahmins in Chola kingdom and the Cholas was the Vishnu beliefs and the motivation of Brahmins to promote Tamil as a language. They hated the caste system in its purest form because in Chola Empire there where only thinly demarcated classes based on economics and not the actual vaishnavite caste system.
Now for the Brahmins the guardians of Vishnu worship a kingdom rooted in another religion/ god/ beleif posed a threat and they had to write an epic to gain a psychological victory over the Tamil kings, worshippers of Shiva, promoters of a language and literary works in a language other than Sanskrit. Hence arrived Ramayana, which in its ancient and purest form has no mention of Shiva as supporter of good. Why else would Ravana have to derive his supernatural powers from Shiva and then Vishnu have to incarnate himself as a human being to kill Ravana. Doesn’t it sound like an illogical waste of time for two gods to go through this excercise. Now in the current world and after Krishna deva raya installed the nayakkars in tamilnadu, vaishnavism and shaivism were intermingled but in ancient world they where distinct religions. Extrapolating to the present we can probably infer that Ram Sethu is just a farce based on a story that was required in time that existed 2000-3000 years ago. Times have changed, needs have changed, if we don’t change with times we will only be left behind.