India is very different from lot of other nations of the world. The only thing that connects Indians and provides mutual existence is the "English Language".
While Hindi as a language not only connects as one of the regional language of the country but also as a religious language.
India in its diversity can only survive if mutual understanding is given to other languages and cultures spread throughout the country. Imposition of any regional language at national level will create a existential threat to diverse cultures, identities, customs, traditions, languages, dress, etc., of the people residing in the country.