It can create conflict and make certain languages feel like they are less of a community because not everyone would be able to understand one another. People might also make certain languages feel like they are insignificant compared to others
B) India has an especially high overall population. It's right after China when it comes to population, and it has over a billion people. Using a little math, even if you have a large Muslim population but over a billion people in your country, the percent of Indian Muslims will be small.