2) for vote to increase/decrease ranking in HN submissions list (value of exposure to HN community)

It’s obvious some people use their votes to reduce the visibility of stories or points of view that they don’t like, rather than according to whether they find it to be of value to themselves and others. By splitting one’s vote one could still express their sentiment without that being tied to their judgement on value. Another option would be to put said info in the comments. But. Come on. We all know that doesn’t happen. Just a thought.