People are subject to criminal penalties (and other kinds of violence) for political reasons, and for refusing to participate in politics. Voting can be seen as a ritual similar to other religious rituals, and not participating is a crime in some countries.
In some un-free countries such as North Korea the purpose of voting is co-opted to mean something completely different: the ritualized political humiliation of the population. By forcing you to vote in an "election" that everyone knows to be a fraud, you're forced to humiliate yourself and by extension delegitimize all voting processes everywhere.
