In every project there's got to be "some person or small group who will make the final decision when everyone else disagrees." Usually it's the person who holds the keys to the last gate barring entry (commit, changes to wiki page, etc). Some times this person is explicitly dictator, sometimes merely implicitly. It's possible that there are projects where the keyholder is given that position by democratic process, I suppose. But often is the case where they're just one of the people who started the project, and happened to be the one who owns the computers, or set up the repository.
It's really not a bad thing, because they have the power to ensure the project keeps moving by being able to add "and that is the final decision" on to things when debate gets too messy.