As any junior high choir teacher can tell you, you don't get harmony if everybody sings the same note. You also don't get change, or protection of minority rights.
Many people think democracy is about majority rule. An election or an issue comes along, and whoever cares enough to vote, does. Whatever candidate gets the most votes, wins. Whatever the result is on the issue, stands. That's democracy, right? Wrong. That's dictatorship of the masses, something Aristotle warned us against.