Those who vote, and those who do not vote, all have an equal right to complain, as all have participated equally in the process. Some people think that if you vote, then you've participated, and therefor have the right to complain, while those who haven't voted do not have the right. They also think that if you haven't voted, then it absolves you from responsibility or any consequences of the results of the elected leaders. Some even think that if they didn't vote for the winner then they can't be held responsible for how bad a leader the winner turns out to be ("I didn't vote for him, he's not MY president!"). Some even think that if you haven't voted then you haven't participated in getting us to where we are.
Nothing could be further from the truth. Those who do not vote play an equal role in steering things, both in the past and in the future, just the same as those who do vote. Everybody has the same responsibility as everybody else, just as everybody shares the same consequences. It's true that "the country is in the state it's in because of what's been done, not what hasn't been done," but not voting is an action just as real and just as affecting as voting is. Every vote cast, and every vote not cast, has precisely the same impact on the outcome.