Language could be a tool or medium of communication but the mother tongue is different. It is not just a medium of communication but also a manifestation of emotions, culture, tradition, values and more importantly, provides an identity to its speakers. Every society that used a borrowed language as its conversational language suffered from an identity crisis or took the identity of the borrowed language. All the nuances and subtilities of literature, culture and art of society are hidden in the language used in that society. Whenever a society could look beyond the instrumental value of a language, they were able to develop independent literature, art, music, dance and culture.
For e.g Tamilians takes pride in their language and refuse to promote any other language other than their mother tongue and English. This attitude resulted in the independent development of literature(Sangam literature), cinema(Kollywood), dance(Bharatanatyam), martial art(Silambam), music (Carnatic music - yes Modern Carnatic music is based on musical concepts like Swara, raga, and tala that were described in the Silappadhikaram by Ilango Adigal).
- 90% of Nobel Laureates (except Nobel peace prize) before 2017 studied in their mother tongue
- Every visiting VIP's speak in their mother tongue as a mark of self-respect
- The notion of English being necessary for scientific innovation is wrong as 90% of the top 40-50 countries in the World Innovation Index impart education in their mother tongue.
Imparting education in the mother tongue provides better understanding than any alien language. At the same time complex, scientific and technical terms should be simplified in Target Language to meet the modern needs of the society.
But this doesn't mean ignore the world's most important language English. English should be studied in addition to one's mother tongue. Learning English has its own utility. Most of the original literature on science is in English. Important concepts could be lost in the translation. Therefore knowing English will give easy and authentic access to 80% (Pareto optimality) of modern science and technology.
English is already a Lingua Franca of the world. Therefore it can also act as a Lingua Franca of India. Promoting English over Hindi as a lingua Franca of India resolves sentimental issues associated with the imposition of Hindi. It gets a ready political acceptance esp. by southern and northeast Indian states. It also opens up job opportunities for Indian abroad esp. in America (World's largest economy).