What about regimes that are based on a leader with exceptional incompetence, exceptional stupidity, and overwhelming arrogance?
Machiavelli never wrote the ends justify the means. That is a blatant misinterpretation meant to discredit him. What he wrote is that there are a few ends that justify the use of horrible means such as when using war to found a state, when reforming corruption, and when removing radical elements as a last resort.