Classic case of trees/forest. People should be empowered to vote according to how it best benefits them, not just go to polling booth and write in lizard man who by the way has as much of a chance winning as Jill stein. "It's my vote I'll vote whoever I want" is a childish cry of immature children who just turned 18.
Not everyone votes in terms of a candidates % chance of winning. If you have two candidates that you don't agree with on a variety of issues and it just so happens to have one that you do agree with, what do you do? Do you just shelve your disagreements and vote the lesser of two evils? Or do you vote inline with your beliefs?
People vote with who they tend to agree with for the most part. Obviously the degree of conviction will swing where some people have more conviction and will not vote for a candidate they disagree with, and some are more malleable and will bend to vote for a candidate they disagree with on issues. Even so, it's not dumb to vote for who you believe in one way or the other.
Maybe they don't see the forest for the trees, but it doesn't matter. They may not feel that it is the important part of voting, rather than voting inline with who they feel matches their beliefs more closely.
I don't advocate voting third party, but I refuse to look down on somebody voting for who they think is the best selection for them. It's not childish or immature or even related to age.
I'd love to respond back to you, but I have a meeting to go to.