That’s because it’s an identity thing. And it’s not just religion, it’s also different groups (right?) who have different opinions about what territory belongs to those groups. Is that something which frequently comes up as a subject of debate at table stakes political discussions? I don’t know how common it is for those conflicting parties to interact, but something tells me they don’t discuss politics about it calmly together.
Identity, caste, religion, and ethno-linguistic grouping are the backbone of Indian politics, so yes these things come up whenever any political topics come up