I cannot repeat myself again and again.
"There's already a Bengaluru Rajdhani at 6 AM."
Have you actually traveled in Dakshin Express ? Or Bengaluru Rajdhani ?? Or Yeswantpur Delhi Sarai Rohilla Duronto ??
Why are you getting confused ?? Day time Shatabdi trains have a different set of passengers with different preference, we're talking about overnight journeys and further connectivity.