You're assuming we see all the comments. We can't come close to doing that, and we don't always read the threads in order. I took a look and you're right—the parent was uncivil as well. When you run into a bad comment that hasn't been moderated yet, the likeliest explanation is that we didn't see it.

The thing is, though, that every user here needs to follow the rules whether the other fellow does or not. "Which you seem to lack" was a needless personal swipe.

More generally, your comment was written in the flamewar style. Please don't practice the dark arts here. It's the opposite of what we want on HN. What we want is thoughtful conversation where people who respect one another try to figure things out together. Treat fellow commenters like teammates and you'll be on the right track.

https://news.ycombinator.com/newsguidelines.html