I heard a bit on the radio about a theory conjecturing that people, even groups of people, experience homeostasis in the macro sense.
As was described, people innately resist change preferring the current status. This, their current equilibrium. Small changes (for better or worse) will be absorbed over time but larger more immediate ones are subconsciously and consciously rejected.
Do I buy it? Maybe. It would explain well why people remain in perpetually broken socio-political systems. It would also explain why people staunchly defend those systems.