Short answer
Because most global genetic databases were built on European DNA, and reading Indian DNA against them produces vaguer, less certain results, so India-aware reference data gives Indian readers more accurate answers.
A genetic result is only as good as the population it is compared against. When the reference data is overwhelmingly European, an Indian sample often returns 'variants of uncertain significance', the honest way of saying the data lacks enough people like you to be sure. India's genetic diversity and community-specific inheritance patterns make this gap real, which is why the growth of Indian reference data is one of the most important developments in the field.