> I can't see that your argument engages with anything I've said.

The GP remarked that comments that amounted to "This isn't Reddit. Please keep on topic." (TIR) are worthless. You disagreed, and tried to explain why by suggesting that these comments discourage people from commenting.

My assertion is that not only does this not work within the system of HN, but that the TIR comment itself is of equal or less quality to that of the comment it's in reply to.

> I've spelt out a plausible mechanism by which some comments would add value to the community (by preventing deterioration of standards of discourse).

Yes: discouragement through an off-topic comment that contributes nothing to the discussion. By replying, your vote does not count (should up or downvote), and you also highlight the discussion. In essence, rather than using the existing tools and protocol of HN (voting or flagging, ignoring trolls, and contributing posts that add to the discussion), your simply adding a TIR post.

You've made this claim (thought without specifying why it's superior to the existing methods), and yet ignored the simple fact that a TIR post is just as bad, if not worse, then the post it replies to. At the very least, the post it replies to is at least, usually, on topic (Topicality is, of course, not the sole contributing factor to whether a comment is worthwhile).

> If you want to say otherwise, you'll have to take issue with that argument. As it stands, you've not done so.

Your inability to understand, or simply your attempt to dismiss my argument, does not negate my argument. It's clear to any reasonable person the arguments I made. If you are interested in an actual discussion, make an attempt. Otherwise, you just come off as a troll. Judging by your profile (which does matter, considering the nature of this discussion), I wouldn't be surprised.

> I don't see any reason to accept it, but even if it did we're talking about a specific subset of responses, and so I've presented an argument for why that subset would add value.

You've done so while ignoring the harm that the a TIR reply causes. Maybe you aren't aware of the ability to upvote and downvote (I forget the threshold for those features), or flagging. This is highlighted by your final comment:

> Finally, 'adding value' is more than just 'sparking valuable comments'. Comments can add value without sparking valuable comments by, e.g. re-enforcing valuable community norms.

Yes. Adding value is more than just sparking valuable commentary or discussion. What you fail to grasp is that your support of TIR is in direct contrast to valued community norms. We have tools (upvotes, downvotes, and flagging) to handle these issues already. A TIR does not enforce these norms, and in fact, flies in the face of what the community wishes to be.

These are outlined here:

http://ycombinator.com/newsguidelines.html

The two that are important to this discussion are here:

"Please don't submit comments complaining that a submission is inappropriate for the site. If you think something is spam or offtopic, flag it by going to its page and clicking on the "flag" link. (Not all users will see this; there is a karma threshold.) If you flag something, please don't also comment that you did."

And:

"If your account is less than a year old, please don't submit comments saying that HN is turning into Reddit. (It's a common semi-noob illusion.)"

TIR very much falls into both those categories. Submissions are not just news stories, but comments as well. If something is worth of a TIR comment, it also means you should just flag it.

Yes, public shaming (what TIR amounts to) can be effective in other environments. HN chooses not to work that way. It's what makes the community so mature and effective.