Why vote?

I've already started hearing the resigned phrase, "Oh my vote doesn't matter, my state will be going _____ anyway." The idea being, I suppose, that if your state historically votes for the Barking Spider Party, then your Pyscho Kitty Party vote will be worthless and pointless. And I'm tired of this argument.
We do not vote because our individual vote will decide an election. And frankly, if an election did come down to 1 vote there would be numerous recounts and it would eventually come down to something like 200 to 20,000 votes. So, we don't vote because our 1 vote is going to elect a candidate. Even if we eliminated the Electoral College, 1 vote would still not decide an election.
So why do we vote? I read an intriguing article about this question a few years back. The author, Gene Weingarten, applied a principle of morality derived from Kant: the idea that an action is moral or immoral based on the impact if everyone did it. So, if everyone in America refused to vote, then the system would collapse. Therefore, not voting is immoral. If everyone in America did vote, then the system would work. Therefore, voting is moral. (The article was in the Washington Post magazine, sometime between 2004 and 2005).
In my own world, this is why we vote: We vote in order to validate the system of government we choose to live under. Our government is "by the people" and "for the people." Our vote says that yes, we are participating in government. Our vote says yes, despite the flaws of America, and even if my candidate doesn't win, I will participate in this system because I believe it is the best form of government out there.
I'm voting this year. Because my vote validates the entire system of US government. Because not voting is immoral. It's not about my vote determining the election: it's about my participation in the system, my voice in this government.