You can disagree with me… apart from her being selfish, manipulative, paranoid, and power hungry, Cersei wasn’t exactly a bad ruler, though she wasn’t a good queen either. In fact, after Robert died, there was no real stability in King’s Landing until she took the throne. She was genuinely shocked when Joffrey demanded Ned’s head, but she wasn’t a good mother, she failed to train her children and even failed to put Tommen on the right path. And blowing up the Sept?… no different from Daenerys laying waste to King’s Landing. Both were acts of revenge without thinking.