Do you vote?

[Sasaki Kojiro]

Not really, as it is the voting that matters. So saying "if you can't be bothered to at least vote, then you can't complain". Those are just optional extras.

That's an arbitrary judgement though.

-edit-

Basically "if you don't vote you can't complain" is just one of the things people say because they think people should vote, and it makes a handy reason. Like "cheating doesn't get you anywhere" as a reason not to cheat on tests.