Okay, this was one of my major beefs w/ BRC's Mahabharata, and now this serial is repeating it - how the division of the kingdom is the worst sin a ruler can do.
Uh, sorry, but that was very much consistent w/ tradition. For instance, Rama had all his 8 sons & nephews bestowed 8 different cities to rule - they weren't all put under Kush. In the Chandravansh itself, Yayati's 5 sons each got different kingdoms, and then the empires did further subdivide as time went on. Like Pratisthana (later Prayag) was certainly not a part of the Kuru kingdom, even though Yayati & Puru ruled it.
This is what the MB actually says about the decision to partition the kingdomAt last the Pandavas, on arriving at the place, worshipped the feet of Dhritarashtra, as also those of the illustrious Bhishma. They also worshipped the feet of everybody else that deserved that honour. And they enquired after the welfare of every citizen (there present). At last, at the command of Dhritarashtra they entered the chambers that had been assigned to them."After they had rested there for some time, they were summoned (to the court) by king Dhritarashtra and Bhishma, the son of Santanu. When they came, king Dhritarashtra addressing Yudhishthira, said, 'Listen, O son of Kunti, with thy brothers, to what I say. Repair ye to Khandavaprastha so that no difference may arise again (between you and your cousins). If you take up your quarters there no one will be able to do you any injury. Protected by Partha (Arjuna), like the celestials by the thunderbolt, reside ye at Khandavaprastha, taking half of the kingdom.'"Vaisampayana continued, 'Agreeing to what Dhritarashtra said, those bulls among men worshipping the king set out from Hastinapura. And content with half the kingdom, they removed to Khandavaprastha, which was in unreclaimed desert. Then those heroes of unfading splendour, viz., the Pandavas, with Krishna at their head, arriving there, beautified the place and made it a second heaven