Why is Dragon Ball Z Kai ending at the cell saga

Toei Animation created Dragonball Z Kai for the anniversary of the original Dragonball Z series as a revision, removing most filler episodes and scenes from the anime to make the episodes faster paced.

While it's not known why they didn't revise the Buu saga, it's probably because it was too long. The rest of Dragonball Z, meaning after the Cell Saga, is episodes 195-291, nearly a hundred episodes. Most of which isn't filler, so it was probably to take a workload off of Toei because they had a strict schedule to stick with.

If you want Nicktoons to air everything after the defeat of Cell, you'd probably have to write up a petition to ask Nicktoons to license the remastered version of FUNImation's dub.

I wish they would have done that instead of going straight into GT. It makes me feel like all the kids who never saw DBZ before won't know who any of the characters introduced in the post-Cell arcs.