I have mixed feelings about the orange highlighting.
Yes, I think it will help improve the quality and perhaps brevity of comments, and I think it sets up a visual caste system.
Writing and getting comments upmodded make me feel a little better - a little recognition but reading comments (or listening to them via TextAloud) is why I read News.YC.
I comment frequently but sometimes sporadically, and I comment to try to add value to a discussion (e.g. point out something I've read before) or sometimes for the heck of it. I think it's good to express opinions.
I remember at one point making it onto the top 100 'Leaders' in News.YC and it felt great. I felt like I was competing with swombat for the bottom 5 spots. I think this was around when swombat had 1300 or so karma. He now has 4924! Amazing. Consistency. It is nice to be recognized but it is fine with me to just be a small fractional part of this community, and it is hard to be consistently be a quality contributor (like swombat and others).
I fired up a Google spreadsheet to see why I wasn't orange (3.04 with highest thrown out vs 3.64 included).
Perhaps median would be interesting to look at, or 90th percentile?
With average, witty, or emotionally-moving one-liners will gain a disproportional impact as they are easiest to upvote, and as such, these items tend to be runaway karma-catchers.
When you say you've learned your lesson, do you mean you'll upvote thought-provoking, longer comments in the future? If so, I wish you good luck, but I'm skeptical about your potential success.
I've had my news.yc account for almost 2 years now, and it has always worked this way. Pithy 1-liners get upvotes; longer thoughtful comments often languish.
We're all in a hurry, so we're more likely to read shorter comments. The longer a comment is, and the more it makes us think, the less likely we are to expend the effort. The most valuable comments are ones that can change our thinking, and by nature such comments will seem wrong or unimportant when we look at them with our current thinking. The problem is human, not technological.
It's easier for me to change what I do than to change what others do, so I've adjusted my comment style to be shorter. Sometimes that means I pass up the chance to share deep thoughts. Other times it makes me more effective. For example, both ericb's and my comments made the same point, but mine drove it home better, didn't it? Upvote with a clear conscience. :-)
I've likewise been here a while, and it has had an effect on my commenting style too. (Albeit almost the opposite.) If I think of a witty one liner or a joke, I'll resist posting it (where before I would have gone for it), because I actually consider whether it'll just add noise.
I also try to be more concise with my comments. Often times I think I have a point to make, but after writing quite a bit I realize that I'm just reasoning in circles and have no ground to stand on. If I can't state my point briefly (and then add elaboration to support it), then maybe I don't have one.
It says something about a site whose culture can make me abandon a position because I realize it's unfounded as I try to articulate it.
As for the one-liners. I'd like to qualify that I'll still upvote them if they are truly insightful, but I'll think twice if they are merely witty. As you say, good comments teach us something new.