Isn't voting for Jill Stein or Gary Johnson like voting for Trump?

Why don’t Jill Stein an Gary Johnson stop running for presidency?
Don’t they know they have no chance? Aren’t they way more like Clinton than Trump?

http://www.cnn.com/2016/09/23/opinions/a-vote-for-jill-stein-is-a-vote-for-trump-kohn/

http://hotair.com/archives/2016/08/02/polls-show-gary-johnson-taking-more-support-from-clinton-not-trump/
I don’t know the sites above,