And yet if nobody voted it would register on their radar.
True, but illogical. They'll always vote for themselves. It's not like everyone won't vote so, therefore, no one will be elected. How many times has that ever happened?
I've seen some elections where only one person was running for a position. Sometimes I vote for them, sometimes not. By voting, however, I register "on the radar". Mayor may reap 40,000 votes out of 60,000 voting, but a judge running unopposed may only have 20,000 votes. What kind of message does that send? It says the judge isn't very popular and, in the next election, maybe someone will step up and challenge them for the office. The judge, knowing this, may decide to conduct themselves a little differently knowing he was elected by only 30% of those voting.
He probably won't give a shit about eligible voters who stayed home, but he'll certainly care about those who actually show up on election day.