The way things are set up now, all it takes is a single downvote to completely hide a comment, which vastly reduces the chance that anybody else will even notice it's there to vote it back up.
I think there needs to be either 1) a delay of perhaps one day before a new comment's rating takes hold, unless that rating reaches a certain low threshold like -3, or 2) new comments get a higher initial score like +3, so it's less likely that a comment than most like but only one dislikes ends up hidden as if most dislike it.
I like option 1 better.
Updated by SirAntagonist