The default position seems to be we're supposed to applaud certain things automatically... anything YC-funded, any attempts to dislodge Flash using js/canvas games that are garbage by post-1980 standards, ridiculous stuff with CSS.
Some of the stuff and companies applauded on here are in my opinion really, really weak. There's no downvoting of submissions so you can only express dislike in a comment.
Unlike actual disagreement, mere dislike is not informative. Just saying that the post is not for HN will get you down-voted, and the guy who writes that you should just click on the stories you want to see on HN will get as many up votes.
Mere Dislike doesn't explain the top comments that disagree.
It could be that someone who doesn't like a story thinks about how he could disagree with it, and write the comment in the hope that it will stop the story to get up-voted. But that strikes me as a bit convoluted.
Some of the stuff and companies applauded on here are in my opinion really, really weak. There's no downvoting of submissions so you can only express dislike in a comment.