Andaman is very very nice and would be ideal for tourism. As is Lakshadweep (north of the Maledives).
BUT

Due to the strategic military importance and (partly) to save the pristine nature the Indian government doesn't actively promote tourism in these islands. Having anything close to the shoreline for example is not allowed anywhere in India, overwater bugalows like in the Maledives would be an absolute no go. The Indian tourist that venture there have very little respect for nature either, I recall an Andaman snorkeling tour we did in the 90s where people had no clue about the preciousness of the nature they were experiencing.

In a way I'm happy things are the way they are. The main island is overrun with government and military families and the local tribes are being sidelined in a bad way. If tourism picks up the situation will be worse. That said I doubt anyone from S.E. Asia would vacation in India?