Passengers coming from long distance generally travel to Junction station or capital area. So they prefer Howrah, Kolkata or atleast a junction station like Bandel so that they can reach their destination by changing the connecting train.
This Balurghat-Nabadwip Dham exp reaches Nabadwip at such a time when there is no connecting train to Howrah or Bandel.
Even...
more... pilgrims who want to go Mayapur they even not get any local transport or ferry to reach there.
I don't know whether you are aware or not, ISCON already asked Eastern Railway to update the timetable for this reason. I will attach that letter here if I found.
Also, back in IRTTC 2019, it was Eastern Railway's proposal to Railway Board to extend it to Bandel. Will attach that as well for reference.