Demcracy would only be ethical if it was voluntary. Yes, it is voluntary now in the sense that one can vote or not vote, but one born into a democratic system is not given another option for organizing a society.
Ideally, one would make the choice to form a democratic union with a small group of people whom one knows personally. But even this would be a matter of preference. There is nothing inherently moral about democracy. It is a style of decision making which was necessary to people in times of crisis, when masses had little else to hold corrupt rulers in check than quick, violent decision making. It is unhealthy for a large group of people to follow so closely to methods of organization that were birthed from disorder. The larger the group of voters, the bigger the chances are for fragmentation and divisiveness.
Let voting not be a subject of moral evaluation, but a personal matter one can pick up and put down. Rules to a game one can just as soon stop playing.