It's true that that phrase is a bit harsher than what we usually post. I use it in a somewhat precise situation: when an account's comment history shows that they've been breaking the rules habitually. That's a worse situation than a one-time offence and seems to merit a stronger tone. Also, I've noticed that some people don't get the message unless the volume is turned up that way. It's hard to predict whether a user is that sort, or someone who would respond better to a softer touch. I presume you would be the latter.

If you can think of a better phrasing that I could use that covers the above issues, I'd like to hear it. And if you'd read https://news.ycombinator.com/newsguidelines.html and only post in the spirit of this site going forward, I'd appreciate it. Other links to take a look at are https://news.ycombinator.com/newswelcome.html and http://www.paulgraham.com/hackernews.html.