I have been Rajghat and have seen that. It is not Gandhi who sculptured that and again it was dramaticized by these facist forces.
When you are vocal about existance of god, why cannot there be someone who is vocal in opposing that. I am not an atheist Hindu but still fell that there should be such counter views for a healthy religion.
Being a Hindu, Karuna can criticise Hinduism and not other religion. He has every right to criticise the religion/caste which comes with his birth.