Is should be just yes or no you handicaps. If you don't know, or don't care, then don't loving vote.
You're the handicap here, the undecided vote is a very important one. If a vote with two options had 3 votes for yes and two votes for no, the majority would be for "yes". However, if the poll included an undecided vote and there were 20 additional votes for the middle option. All of a sudden, the statement "60% of people voted yes" becomes completely untrue