HN is filtered. The main page is a list of article which have been selected and upvoted by small unrepresentative subset of the population. I agree that it's not personalized though.
Then click on "new" (it's only one click away), and you'll see everything that's submitted. If you change your profile to have "showdead" = "yes", you'll really see everything - even the stuff that's flagged or downvoted to oblivion.
