I guess in my thinking, if the act of not voting means you are okay with letting the worst candidate win, then by not voting it means I'm okay with a lot of innocent people being hurt by the horrid policies of the worse candidate. By voting for the lesser of two evils, I'm more saying "I don't want that other candidate".
You're trying to say it's their plot to give you two candidates. What if their plot is instead to convince you not to vote, so their bad candidate gets in easier because you could have helped stop it?