Greek democracy was established because of the idea that a person
shouldn't be too powerful and rule the lives of others. They were so
ruthless at it that they would choose people to rule and then if they
became too powerful and popular they would exile them or punish them or
similar things. It was a kind of mob mentality that supported new and
popular people. It was not very democratic however according to modern
understanding of democracy because many were not allowed to vote at all,
including slaves who existed as an entire social class.