On the one hand, most people agree that the Sentinelese people have a right to be left alone. On the other hand, they just aren't going to be left alone forever. One foolish man tried to convert them to Christianity this month. Fools are like roaches, there are many, many more besides the one you just stomped on. If the Sentinelese don't die out from a disease brought by this most recent intruder, they are still at even more risk than ever before.
Some might try to convert them again, someone might try to recruit them for a cult, someone might want workers for a new sneaker factory. Their best hope for survival is a well-planned intervention. The first step to helping them is gaining their trust and consent. The first step to gaining their trust is to establish contact. The safest way to establish contact is to send an arrow-proof robot with a video screen to the island. And even if the natives don't destroy the robot or ignore it, it will still take years before linguists learn enough of their language before their can be any mutual understanding.
If the Indian government isn't willing to allow this, these people may die out within a few years.