This is the basic problem with direct democracy. You have to assume that everyone knows enough about everything to be able to vote meaningfully, and that everyone will be completely moral about how they vote. When a vote is brought up to extend that sewer system into an area which is predominantly Muslim, say, how many people will do the humane thing and vote for it, and how many will let their prejudices hold sway, as so many of us are wont to do so often.
Direct democracy might work for some things. If your bridge club elects to change the day of the week they meet on to suit the majority, you either live with it or leave. If your town votes to cut off essential services to the slum area, people die. Not the RIGHT people, of course. Only those different, poor people.