I'm sorry but what makes it a swipe is that it's a low-information putdown (and even a cliché of those). That's the high order bit, not whether it was an opinion-earnestly-stated, because it's what determines how the comment lands with the other user in the typical case, and that's what determines whether we get more interesting thoughtful exchanges, or less interesting flamewars. This case ended up being typical because we ended up with a flamewar of the tit-for-tat variety. That's not what HN is for!

(As a side note, one reliable indicator of thread deterioration is when people start arguing about what each did or didn't say.)

Instead of putting down the other person's knowledge level, it would have been better to share* some of the specific goings-on of early cipherpunk mailing lists, since you obviously know something about that. That would have gratified the curiosity of the general readers (me included!) and this is more important—it is in fact the purpose of the site—than defeating somebody in an argument.

As for the other user getting flagged, I appreciate your looking out for them—but it isn't about either you or them, it's about the general audience, which comes here hoping to read things that are more interesting than putdowns and tit-for-tats. We have rules (https://news.ycombinator.com/newsguidelines.html) that try to encourage that and discourage the opposite, and when people break those rules, it's good to mark that by flagging the comments because it indicates to the rest of the userbase that concern for discussion quality remains present here.

* https://hn.algolia.com/?dateRange=all&page=0&prefix=true&sor...