Just because you have the right to do something, that doesn't mean you should do it. I have the right to hiss at ugly people. Doesn't mean I should do it. And while I believe strongly that MOST people should vote, there are about 5-10% of people who should just stay home on Election Day, and we should all be ok with that.
Here are some criteria you should think about when deciding if you should vote or not.
1) Did you think the Duck Dynasty guy had his first amendment rights violated? If so, you should not vote, because you don't understand how stuff works.
2) Are you only voting the way your parents/pastor/deity-of-choice told you to? Don't vote. If you didn't make up your own mind, your vote doesn't count. It also doesn't count if you are only voting the way your friends or some cool celebrity is voting.
3) Do you have a general sense of what the issues are, and where the candidates stand on them? If you are completely ignorant, and have no idea what's going on the the world, and you would basically be selecting a candidate at random, don't vote.
Yes, I know it's our civic duty to be aware of the world around us and to take a stand and vote accordingly. But if you haven't been keeping up with things, for whatever reason, don't compound your error by making an uneducated vote.
Most people should definitely vote. But I think recusing yourself because you lack the knowledge to make an informed choice is perfectly valid and reasonable.