If I filter out the exceptional narcissism on display here (particularly in the postscript), I think you make several points that I both agree and disagree with:

1) >When I see something overtly bad: a troll, something irretrievably wrong from a technical perspective, or an over-the-line personal attack with no redeeming content, I'll reliably downvote it.

I think this is good. I don't think anybody will argue with you on the merits of this kind of downvoting. In fact, on some level, most people would even think you are too light on trolls and the like since there is a flag option intended for just those kinds of users.

2) >Otherwise, I don't vote. I'd rather reply to something than vote it down anonymously, and if you're going to reply, downvoting the parent is counterproductive; it effectively asks the site to bury your comment along with the parent.

Again, I think this is good. The purpose of a forum like this is to drive discussion not karma building. Comments as replies with or without a vote up/down is far more valuable than an anonymous vote. I think we also agree that downvoting can also have the effect of "tainting" an entire thread so that further responses are also downvoted or nobody participates in that entire sub-tree. I applaud your willingness to participate and engage in this site via contributing comments and discussion. We've butted heads here before as well, and I enjoyed every bit of the engagement despite our strong differing opinions.

>I'm sure I routinely downvote things out of pique just like everybody else, and I'm sure I occasionally upvote things too. Those events cancel each other out. Meanwhile, I'm still reliably downvoting bad stuff. Hence, 65%.

Actually you would be over 65% since the site's logic no longer allows you to downvote (at least according to pg). 65% is the cutoff, given no limit you would probably be much higher than that.

> I just want to speak up in defense of the idea that up/down percentages don't matter.

I most strongly disagree with this. By force of logic, if they didn't matter, there wouldn't be a cap...period. The fact that there is a cap is designed to control for users of the site such as yourself.

And you are right, it doesn't matter what I think, I'm just a low karma user that writes too much. However, it does matter what pg thinks, and he thinks that up:down ratios like yours represents such bad behavior that he took the time to build a control into the site explicitly for that purpose. You, I and pg agree, there is a body of users on HN that represent abusive downvoters -- hence the control. You simply don't think you are part of that group for some reason.

> Like short sales, downvotes contribute to the efficiency of the site, just like upvotes do.

I do not disagree with this, hence the existence of a downvote mechanism. Like negative feedback in any social situation, it's a social normalization function designed to move a person towards an equilibrium of thought and action with their social group (just like my negative feedback to you is intended to do). I'm not sure it's always helpful since it tends to suppress out-of-the-box thinking as well as bad behavior, but it is there.

However, you and I must read different HN sites. Unless you spend your entire day policing http://news.ycombinator.com/newcomments and downvoting "trolls, bad info and personal attacks", or you vote so seldom that a vote either way makes up a large percentage of your total, I simply don't see a particularly large number of posts on this site that fit into your three criteria. I may be mistaken, but I'm guessing that pg has also not deputized you in some fashion as a body responsible for policing HN -- feel free to correct me on this.

I personally think that the user community on this site tends to not skew towards those categories which is one of the reasons I enjoy this site so much.

Please don't take this as a personal attack, I know that your intentions are good. But you seem to be the only habitual downvoter that has decided to make themselves known to the user community at large so my focus is on you. Really, my focus is on the group of such like-similar downvoters since they represent a significant portion of the small list of reasons where I don't find this site enjoyable.

p.s. I upvoted your comment.