That says nothing. Why is that better than voting for a third party candidate? By voting third party, you show what you would prefer in a candidate. Even if the Green party or Libertarian party will never win an election, their costing a major party candidate an election by siphoning off voters that would have gone to him tells the Republican or Democratic party what issues they should address for the next election.

You statement is roughly equivalent to saying "rather than offer a dissenting opinion, wouldn't remaining silent be a better way to get people to do what you want?"