What Michael Moore fails to realize is that every time we spend our money, we are in fact "voting".
We vote with our wallets everyday!
The companies that don't get our money, are voted out!
That's why it's so important for our government to not interfere in the people's "vote" by bailing out the failed companies or giving certain companies unfair advantages and special favours..
Reasons to vote
Turnout by country
http://www.idea.int/vt/countryview.cfm?id=15 (even Australia does not have 100%)