If I were doing it it's easy. The flippant monarchs acquiesced to the masses at the request of a corrupting influence. What is the push-back for that situation? Simple, the upper-class. Forces immediately bellow the Diamonds do not like the democratic changes that are being introduced at the request of this corrupted Pink Diamond impersonator. Sure, the Diamonds get to keep their status; they are, after all, the progenitor of all gems. But what of the Agates, the Emeralds, the Spinel? Even the Zirchon are up in arms about this. It is a threat to their way of life. The Diamonds might be iconic, but they are brittle and few, whereas the upper class, their connections, their production lines. They ARE the Empire. The Diamonds want to re-write the rules? Well then they will SHOW them a new set of rules.
-Alternately, more suited to a movie idea-
The one called Snowflake, the Star Sapphire, the Crown Jewel of the Crystal Gems and Blue Diamond's great Judas. She turned traitor not because she sought a life of acceptance and free love, but because she recognized value within the organic life, which grows relentless and competes and consumes itself. This evolution, this directedness, this adaptability. A deep and inky compassion driven not by want, but by need. The dragon, Star Sapphire, who has been awakened to an era of acceptance and acquiescence. Realizing that none among her saw what she saw, felt what she felt, realized what she realized. Takes up arms against the established state. Recruits humans, recruits the disenfranchised warriors and competitors among the Gems. Seeks to build an army, a movement, tempered by resolve.
Well, neither of those things are happening. Just fanfic'ing. ANYWAY.