1- Is it really a problem for the thread? If nobody agree with my comment, is it a so wrong action to pseudo-hide my comment to next readers?

2- Why users with karma will have a better understanding of downvote than the passives old-regular-readers? Peoples who read HN every days love the high level of the comments here, let them have produce some feed back. Note that I just defend my interest: I'm not good at creating comment with value (so I do not comment a lot), but I feel confident to reconise good comments from bad comments.