Even the dedicated weekly they run is horribly slow with lots of slack. So the image created by Railways is that trains are horribly slow so just take the buses and take train only if it's your last resort.
Check the schedule of this one trip Suvidha Special which ran in December:
/train/55222/512/997
It was given a very fast schedule compared to...
more... the regular crawlers, if the present biweekly is scrapped and a daily train is introduced with such fast schedule it will be a hit.
But then again the bus lobbies would be upset and SWR won't let this happen as they are both lovers on fire. Lol.