In small groups where decisions must be made in a timely and decisive manner, a mediocre leader is often better than the best democratic committee. Even in programming teams, somebody needs to put their foot down eventually or things will be bikeshedded to death. FOSS projects too, generally benefit from a BDFL.
Be careful about extrapolating this out to the rule of countries though, dictatorships can make things go south worse than any other system. At least with FOSS projects, people can fork without fleeing their homes.
