For what it's worth, let me narrate experiences of mine which may have some relevance in the context of this discussion.
While on a visit to Japan in 1959, I met K V Paul, whom C Kesavan mentions in his autobiography "Jeevithasamaram". He was a senior colleague of Kesavan at a school at Palakkad where he had taught for a while before plunging into politics. He has written in glowing terms about Paul and before going to Japan I collected Paul's address from him. Paul had married a Japanese and settled down in Kobe as a businessman. I travelled to the city to meet him. He asked me what was the Japanese method of paddy cultivation, which was being promoted by the Govt of India at the time. I pleaded my ignorance about agrarian practices and said I presume that is the method followed in Japan. Where do you think the Japanese got it, he asked me. I again pleaded ignorance. He told me the Japanese method of paddy cultivation was exactly what was being done traditionally in Kerala. He claimed the Japanese were of Kerala origin. He pinpointed their place of origin as Thiruvilvamala, his own place. I asked if the Japanese are not supposed to be the product of the mixing of two streams of migrants, one from Malaya region and the other from Korea? Where do you think the Koreans came from, he asked. According to him, the Koreans too were of Kerala origin. I did not take Paul's claims seriously. A few months after the encounter with him in Kobe I was in the Asiana section of the library of the University of the Philippines and found there a small book titled Culture of Korea published by the Korean Association of Hawaii in 1901. Korea was under Japanese occupation at the time and the Koreans received little support for their struggle for freedom from the Japanese yoke as most people thought the Koreans are no different from the Japanese. The book carried a note by Dr Singman Rhee, who was president of the Korean Association of Hawaii, saying it was being published to give the world an idea of Korea's culture which was distinct from Japan's.. When I picked up the book Rhee was the President of South Korea.
I flipped through the pages of the book and found this sentence under the heading Language: "The Korean Language belongs to the Dravidian group of languages spoken in the south of India."
The Japanese language is said to have affinity with Tamil. According to Japanese tradition, the first Japanese work of grammar was written by a Buddhist monk from India, who introduced in it elements from the grammar of Indian languages. Foreign scholars have pointed to similarities between Tamil and Hebrew on the one side and Tamil and Japanese on the other. I don't think there will be any academic studies on these subjects in India. Hindi-Sanskrit votaries will not want any studies which may show that Tamil had links with West Asian and East Asian languages which go back to an earlier period than that of the Indo-European languages. The Dravidian politicians do not want any studies that may establish links with other groups as it will explode the myth that the Dravidians, unlike the Aryans, sprang up on Indian soil.