I rarely tell people that I don't believe in voting. Participation in the body politic is widely considered to be both a privilege and an imperative to the enlightened urban citizen. To choose otherwise is quite literally heresy – and heretics by and large have a difficult time of it in society.
The platitudes I face as a non-voter are known to everyone, precisely because they are platitudes – People have marched for miles! or Immigrants crossed oceans! The fables are beautiful and they are compelling. But that does not make them true.
I do not agree that secretly flicking a switch once a year constitutes "making your voice heard". Nor do I think that an annual trip to a voting booth is a criterion for whether one can complain or not. My right to free speech is not contingent upon anyone else, no matter how many of them there are, whether they were elected to some office or however much they stamp their feet.