Only once has a third party candidate made much progress, and Perot was right-wing/libertarian. You can't skip right to a third party presidential candidate without making progress with that party locally first, then in Congress. That just how this system works. You can pretend that enough people will spontaneously vote for your same third party candidate, but that's a demonstrably a fantasy. You can claim that a vote reflects on your own morality rather than something strategic and practical, but that's a view pushed by people hoping to take advantage of youth vanity and split the vote.