I would agree that there is no tangible historical evidence of either Ram or Krishna existing. That does not mean you can assume that neither existed. It just means you don't know.
The more important fact is that the Ram setu is of great cultural importance to millions of Hindus. For instance, if Abraham has no historical significance, and one cannot verify that Prophet Mohammad went to heaven from that place, is it fine to destroy the dome of the rock?
I believe that the government should consider the religious sentiments of countless Hindu and choose an alternate pathway. Following is the most troubling statement in the entire report:
"The Centre and state of Tamil Nadu are hell bent on removing Ram Sethu as they have refused to take any of six alternative routes suggested for Sethusamudram."