Air India

Why is Air India ALWAYS Mumbai or Delhi centric? I am not questioning the decision made by Air India, but trying to understand the need for a flight to the US from these airports, where handful of flights are already available. I keep guessing if Air India knows that scores of Indian citizens in the West come from South India, nevertheless to say for IT jobs. And unfortunately there are no direct flights from any of the southern airports. If Air India presumes that its flights will be empty, I am wondering how Lufthansa, British Airways, Malaysia Airlines and Singapore airlines always fly with full capacity to the airports like Chennai ,Bangalore & Hyderabad! It is not a question of North or South divide but it is high time for Air India to be available for the entire nation and not just for few cities which it thinks deemed fit.