There are plenty of reasons not to vote for either of the two main candidates.
You don't have to vote (assuming you are a gringo). Here in Australia, we would be legally compelled to make a choice, or face a fine for not doing so. I actually think that is a good thing, that works well for us, but I do very occasionally perform an act of deliberate civil disobedience, and pay the fine. And sometimes I just forget, and pay the fine.
I do suppose - and hope - that Romney's halo resulted from poor technique rather than a deliberate attempt to make him look good in the eyes of some voters. The opposite of that does go on. Images of Obama in Romney material, and vice versa, certainly don't show either of those two fine men at their best.