It's pointless to comment if one cannot add new information, perspectives, arguments, or humors to the thread, as a result, one really needs to make an effort to engage in the discussion. In practice, it means you'll need a proper keyboard, and a fast Internet connection to search for references. At least, at there, or at Reddit, or even at 4chan, this principle applies. I mean, you can make pointless comments, but you'll lower the SNR of the entire community, or your comment will be ignored or filtered on 4chan, or downvoted (or not getting votes) on HN/Reddit/Slashdot.
There are other places where the barrier-of-entry is lower, like the comments section below the stories on "ordinary" news websites (not HN), etc, but make an comment is even more pointless.
I guess the best counterexample I can think of is Twitter. It's no more than 140 chars and highly personal, so making a knee-jerk comment is common, and you can use a mobile phone instead of a proper computer to do so.
I'd also presume (and it is a presumption!) that people who are commenting on one platform will likely also to be commenting on another. As in, I would presume they would establish a conversation as the preferred method of internet discourse they digest, as opposed to a one way consumption of data.
This also gives me an opportunity to use one of my favourite Cronenberg quotes: "The monologue is his preferred method of discourse" - Videodrome
This is especially true if the content itself gives authoritative or complete information about something, as Warnock's dilemma (https://en.wikipedia.org/wiki/Warnock%27s_dilemma) described:
""" The problem with no response is that there are five possible interpretations:
* The post is correct, well-written information that needs no follow-up commentary. There's nothing more to say except "Yeah, what he said."
* The post is complete and utter nonsense, and no one wants to waste the energy or bandwidth to even point this out.
* No one read the post, for whatever reason.
* No one understood the post, but won't ask for clarification, for whatever reason.
* No one cares about the post, for whatever reason.
— Bryan C. Warnock """
In this way, I think the voting system became popular, not only because it's usable a mechanism to select interesting information, but also gives an important feedback to encourage the poster, same for the "Like" button. However, they has their own problems.
Most people (who can) read. That's a lower effort (and most of the time sufficient) than writing.
But I remember teenage me, over 20 years ago, being very reserved about writing online because I considered my grammar too bad and I didn't want to embarrass myself.
And back then there wasn't even anything social media, where blunders like that could lead straight back to "real" me, the whole idea still made me anxious.
Can't even begin to imagine how teenagers these days must feel with social media being literally everywhere and recording pretty much everything they write for the foreseeable future.
At least nowadays they have access to some pretty good grammar correction tools ;)
You get publicly scored on your contributions to the discussion. Most people are turned off by the idea of discussions being adversarial, point scoring, confrontational.
And in that respect, I consider the barriers to comment contribution to be very high indeed.
Maybe out of fear of saying something wrong and getting debated on it - though it's quite civilized here. They might have seen too much of other websites where things turn less civil :)
I don't know which foster the best quality discussions, but I feel the HN way is a bit impersonal.
In truth the polarizing of the Internet is causing a lot of us to be lurkers who may have things to say but do not want to engage in emotional content with strangers, because everything is interpreted so emotionally these days.
When I don't see the replies, they're easy to ignore.
At some point (I have no idea when), Reddit also added a "disable inbox replies" button to comments, so that you can prevent notifications on a comment by comment basis.
* is it true?
* is it necessary?
* is it kind?