Without putting much thought into it: "Downvotes mark comments without merit" If something has educational, thoughtful, contrarian (encourages discussion), etc

Without putting much thought into it: "Downvotes mark comments without merit" If something has educational, thoughtful, contrarian (encourages discussion), etc merit it's welcome on HN. If a comment has nothing going for it; is just lame, or a pun, or an unnecessary meta comment, then a downvote makes sense.