Clearly some do, if these stories get upvoted. I think a better answer than downvoting would be a ways to organize and filter content besides the single-channel model which currently seems to assume either a homogenous community or content or both. Clearly useless and repetitive content should be flagged, but judging by the number of "this doesn't belong on HN / yes it does " comments i've seen, a lot of people have differing ideas of what Hacker News "should" be showing them.
> Votes on comments are used to express agreement or disagreement rather than value, perhaps because many people simply cannot see the difference between the two.
I believe upvotes and downvotes should only apply to threads themselves, and comments should be left alone. I'm sure i'm in the minority on this among HN users, but I think when you can downvote comments, then specious downvoting becomes inevitable because it's less work than coming up with a cogent or relevant comment.