Since we are here, Daniel, and also with reference to something I wrote nearby: I think the guidelines should be augmented, in terms of "downvoting without justification should be frowned upon". Otherwise, some would be tempted to just downvote something because they "feel differently": posts are not polls ("how many like strawberry, how many dislike it"). In general, downvoting should be accompanied by posting the underlying reasons - it should take posts evidently inconsistent with the purpose (cheap cheer, cheap joke etc.) to be exceptionally downvoted silently.

I understand HN is pretty conservative in terms of structure and rules, but I believe this should be a general norm that would be consistent with the spirit of the site (intellectuality and promotion of meaningful posts), and beneficial if made explicit.