I think the difference is that the Indians were subjected to colonization, whereas the American rebels were themselves the colonists.

It would be more similar to a rebellion of the British governors/Raj in India against the Crown, which very plausibly would have led to even worse and more prolonged abuse of the native people in India.

One of the reasons the British decided to cut their losses in America was that they had more important opportunities in India, where they were consolidating power after their victory over the French at Plassey.