All were corrupt and oppressive leaders who starved their people and were oblivious to the emerging paradigm of revolution.
All 4 were "average" people that got caught up in events that were beyond their control. All were blamed for all that was wrong with their society; economic, social, personal, political, etc. They were all ultimately innocent victims of collapsing regimes. Even if they had all been politically astute, they still could not have done anything to save themselves.