An excellent point, Kazan.
As a matter of strategy, do you want Obama to retain the Presidency?
I don't want either Obama or Romney in the White House. But, I don't want Scott Walker or the equivalent in it in 2017. That isn't happening if Romney wins the election.
I want whichever authoritarian government statist who wins, Obama or Romney, to be as weak and vulnerable as possible. In order to vote for that, I must forfeit any influence over which of the two menaces wins, but the pay-off is that my on-the-ballot official third-party vote (guaranteed not to disqualify my ballot, as a write-in might) will count toward a split vote plurality, and a plurality win will weaken and hurt the next president -- a good thing since either one is an enemy of freedom and limited government conservatism.
As a matter of strategy, I will be voting FOR a plurality. It's the ONLY way I can use my vote at the top of the ticket to help all the conservatives I'll be voting for down-ticket.