Because India's tribal communities are basically bilingual there is a danger of dismissing their languages as dialects of India's major tongues.

Most of the tribal communities are bilingual. They have assimilated many vocabulary from the major languages of the country. It may seem to many of us that their languages are dialects of India's major tongues.

Another perspective

'Most of the tribal communities in India may be bilingual but there seems no danger of dismissing their languages as dialects of India's major tongues. This only shows that the tribal communities are assimilative in nature. Identity of any language is never destroyed simply because it is borrowing words from some other language. Had it been so then even languages like Hindi and other major languages which keep on borrowing words from foreign languages would have lost their identity. The tribal languages have a structural difference from the major languages of India. Simply the presence of some words of other languages will not make them lose their identity and make them identified as dialects of some major Indian languages.