That is still very much a small minority. For the average Indian programmer in the US, there's very little incentive to move back to India purely for professional prospects. Let's face it, I'd much rather code for Amazon in Seattle than Flipkart in Bangalore.
Other factors like the shitty visa situation (more and more people are chosing to move to Canada because of their permanent residency requirements), family ties and some more ethereal things like the pull of the motherland come into play. As an Indian in the US with maybe 70-80 people from my undergraduate class in the US, a grand total of one person went back to India to build a startup despite having a succesful career.