Consider for a moment: you can vote for spam or canned tuna.
Hilarious.
How do you think you can stage a revolution with a minority of the population behind you, while the powers that be are as well-armed and as eager to use violence as they are in the US?
You've got a better chance of voting both parties out of office with a minority vote, and fixing the broken system that people are so disenchanted with.
Your mistake is that you believe that the options they're giving you are the only ones. You can make a third option. If you can get enough people behind you to stage a credible revolution, you can easily get enough people to vote for your third option.
It's totally true that the US electoral system is broken and corrupt and doesn't do justice to the vote of the people, but it's not yet to the point that the vote doesn't matter at all. People do still need to vote, and alternatives to the two ruling parties are still legal. You can take advantage of that to stage a much more peaceful revolution through the ballot box.