Thanks for the measured response.
how do we determine the value: who should be allowed to vote
To be clear, I believe that everyone should be allowed to vote. I'd go so far as to say that even felons should be allowed to, for fear that the legal system could otherwise be used as a tool to stifle electoral dissent.
My suggestion that some people not cast a vote is intended to be entirely personal, as a matter of conscience and reflection. If anyone honestly believes that his ideas are the product of rational thought applied to an understanding of the situation, then by all means, cast that vote.
I don't think that your murky water criticism can apply, because I'm not asking -- nor trusting -- anyone else to judge. I'm asking for a person's own, honest, self-evaluation. No one else need know if you exercised this option or not, and it's none of their business.
Moreover, this doesn't relate to a single person monolithically. A person might have very well informed ideas about one topic, yet be ignorant about another. The decision ought to be made on a vote-by-vote basis. For example, this morning I did not cast a vote for County Freeholder. Although I know who the incumbent is, and don't have anything in particular against him, I don't know enough about county-level politics, nor the candidates, to make an informed decision, so I abstained. Yet I did cast a vote for US Representative, County Sheriff, etc.
I'm also sympathetic to the criticism that Dunning-Kruger might make this backfire.