The problem is that the proposed solution is more of a mild nuisance than a solid block. If spambots or the human equivilant want to upvote worthless links, it's trivial to hit the link first. The same minor workaround would be required of legitimate users that, as you mention, may have seen the article elsewhere and already read it. And it might make impulsive people more likely to read the article before voting, but again nothing is guaranteed (and is that really a serious problem anyway?)
Minimalism and simplicity work well for HN, and I don't think there'd be a clear enough benefit here to warrant the added complexity and occasional annoyance to legitimate users.
Minimalism and simplicity work well for HN, and I don't think there'd be a clear enough benefit here to warrant the added complexity and occasional annoyance to legitimate users.