I'm hesitant to give the Section 31 writers this much credit, but a recurring theme from Star Trek (especially since TNG), is the notion that people are a product of the cultures they come from, and asks the question of if they can grow beyond it.
This move showed us that Terran empire causes suffering for everyone, even for the top leaders. The system is working for nobody and yet they are all stuck within it. The system of abusing children to choose a new leader seems engineered to make sure that nobody can escape.
Georgiou, somehow, escaped. And now she's (in her own words) "a monster with a conscious (ie: useless)" in a system that has no need for monsters. She felt useless to change the empire, and useless to do anything once she found it no longer surrounding her.