Second, don't make Hindi the marker of national identity. Large population in India never spoke Hindi. The South, North East have their own distinct languages and traditions. As Arvind Ilamaran put it, "to claim that North and South are cut of the same cloth is historical ignorance at best and political malice at worst". Hindi can thus never be made the basis of uniform national identity. There are 122 major languages spoken in India. Andhra Pradesh split up into two because of the discrimination of one form of Telugu in favour of the other. Our neighbours, Pakistan split up on the issue of language. It's foolish to impose Hindi and make it a marker of national identity. It cannot be justified either morally or politically. It will be a historical blunder to do so.
Third, don't bring false equivalence between Hindi and English. It's often question, if you can learn English, why not Hindi? The question here is not about ability to learn a language. English is a utility, hence people learn it. Hindi and other Indian languages have a culture associated with it. Imposing Hindi is thus fundamentally different from people learning English for the sake of utility.
When an Indian PM gave a speech in Hindi in an international forum, many in India applauded for speaking in language he's comfortable in. Why not give that privilege of using one's own mother tongue, to others too, within one's own country?
At a time when everyone in education is talking about instruction in mother tongue, we should also extend this to other arenas of life, facilitating communication in mother tongue. It will make life easier for many.
Multiculturalism should be the way forward.