Voting on HN is not a like, it is about getting the good posts which produce good discussion at the top of the thread so we do not have to scroll through pedantry and nitpicking to get to the content. These posts offering old content are handy things to have in a thread but rarely produce good discussion and the best place in a thread for them is at thee bottom of the worthwhile posts but before the garbage posts which is where a single downvote should get it in an ideal world but people probably just downvote such posts in an attempt to counter the upvotes such posts always get.