Earlier quoted context omitted.
Why does 'nationalism' concern you. Is 'nationalism' always or almost always negative?
A healthy nationalism is something countries should cultivate, in particular to unify disparate minority groups with the majority. A nationalism where a Hindu majority are stripping a Muslim minority of citizenship is probably not the good kind of nationalism.
You have to also keep in mind, when you're asking for nationalism to take the form of unification, to Hindus in India that sounds like asking victims to accommodate their oppressors, given hundreds of years of invasions and brutal occupation of India by Islamic powers and then Western colonial powers. The push from Western actors like America to push for a secular India is equivalent to saying "indigenous people in America need to make way for the occupiers that perpetrated their genocide".