Yes, in the most idealistic sense you are absolutely right. But democracy does not work like this. Democracy depends on commonsense compromise. Half a loaf matters big time. Without compromise there is only gridlock that morphs into brutal dictatorship.
Even the super passionate Senator Sanders understands this. This, however, is what black and white thinking fanatics never get about democracy. No matter how much Bernie has moved Hillary to his principles, it will never be enough for purist fanatics.
They wound prefer a dictator’s concentration camp to compromise of any kind. That is why they are so dangerous. Being right, dead right is no virture. It is only mindless egocentricity in action. You may not care about wasting you vote that may open the door for a Hitler type megalomaniac Trump to trash America, but the rest of us life loving folks absolutely do.