No. Even if the route is circuitous, it's important in terms of providing connectivity. The current route of Budhpurnima is right.
And huge numbers of people board this train for Gaya - Bhabua section especially from Patna.
As Nalanda have a few trains only, the route is important as it is the sole connection to the districts of southern Bihar.
And...
more... for connectivity via mainline, Kashi Patna Janshatabdi should be extended to Rajgir as the rake stays idle at PNBE for the whole day.