Well, if everyone took your advice and didn’t vote, you’d have one moron who walked in off the street decide an entire election, with the only vote. It’s not whether your individual vote matters, it’s that the community of voters decided on the candidate.
This past presidential election should be evidence! Hell, if a very, VERY small percentage of voters had not shown up that day in Florida, there could have been a complete reversal of the election. Sure, a single vote didn’t decide the outcome, but a few thousand votes is where counting each one becomes important, because as Munch stated, 1+1=2…the cumulative effects of our votes are very important, whether it’s a landslide or a nailbiter.
And like rjung said, it gives you complaint rights. IMO, if you didn’t vote you have no right to complain about the outcome of an election. If a bunch of people who didn’t feel like voting and who liked the other guy had gotten off thier asses, the other guy would’ve won. Everyone who has an interest in the outcome of an election and the policies that follow should vote.