It's sort of like, when a British person lives in America they're an "expatriate", but if an Indian lives in America they're an "immigrant".
Just the way the world spins.
(Off-topic non-relevant story follows)
I once flew Air India from New Delhi to Chicago. 15 hour non-stop run. At O'Hare, as we were exiting the airplane the airport (airline?) staff waiting to pick up the wheelchair passengers were saying random words loudly in mock Indian accent and laughing.
I wonder how they greet passengers disembarking a Lufthansa.