For the same reason why the introduction of 16575/76 was delayed for over 3 years - Clearance to operate in the ghat section.
This weekly proposal was made a couple of years ago, by which time even the introduction of Kudla (Now Gomateswara) express was still pending and the KA high court had issued orders to the state government and the railways to introduce the daily intercity train, which did not have any terminal objections from the concerned zones.
This weekly too faced the same...
more... problem as Kudla, having not been cleared to operate through the ghats.