The whole mood of the vrata is that it’s about Kṛṣṇa, but here it’s just all about their inconvenience of fasting. So better they not fast. They will get more spiritual benefit.

CHAPTER 21 started 22nd Apr 2016 Lecture 1 http://seminary.bhaktivedantaacademy.com/content/uploads/2016/05/20160422_SB205_3.78-3.86_Lokaloka_Aloka.mp3 The Universe is set up the way Lord likes it, for the elevation of the living entities, therefore there are different places and different mentalities. We must follow the Vedas, but the whole point of the Vedas is to perform our duties