Current water-carrier here; I find it especially hard to believe that anyone could find a ballot where a few minutes of internet research would not reveal an at least slightly preferable candidate -- if not for you personally, for your community.
Ultimately, I find the supposed "principled non-voter" to simply just be selfish.
Sure, maybe it’s selfish, but so is voting. That’s not a sin.
Voting someone into office is inherently about electing them into a position of power. Generally that means voters are going to prefer someone who is aligned with their interests. If you examine a ballot and determine that that is no one running, then it is fine to draw the conclusion that you would prefer to skip this election.
Voting also has consequences. If your world view is not developed enough to determine who that person would be, it is also fine to wait until you’re older before you begin voting in elections. Elections are recurring, it isn’t necessary to vote in every single one of them, and on every single item on the ballot until you have an interest in doing so.
Ultimately, I find the supposed "principled non-voter" to simply just be selfish.