We know that the sparring between Kruel and MIRI has caused a great deal of harm but it still should be possible in a less antagonistic fashion.

I am not about to mention you just to make your health problems worse, nor avoid mentioning you if I find that a net positive while I happen to be writing; your conduct has placed you outside of my circle of concern.

Not even as a tie-breaker? There are nicer ways to say this.

I urge you to see a competent cognitive-behavioral therapist and talk to them about the reason why your brain is making you do this even as it destroys your health.

This advice seems unsolicited and getting psychological advice from your past competitor seems unlikely to be helpful on an outside view.

I might bring up the name of Alexander Kruel as that guy who follows me around the 'Net looking for sentences that can be taken out of context to add to his hateblog, and mention with some bemusement that you didn't stop even after you posted that all the one-sided hate was causing you health problems.

This seems to be written to make Alexander aware of his risk of later embarassing himself. Telling someone who announces that they have mental health difficulties that have been exascerbated by their sparring with your writing that they're likely to face embarassment if they relapse is somewhat (and unnecessarily) hostile, especially as they probably already know.

For what it's worth, I think that as well as producing much of the least helpful criticism of MIRI, I've also found that reading Alxanders writing has also led me to think of ways that MIRI and LessWrong could improve (getting more publications and conventional status), and to help AI risk advocates to anticipate kinds of criticism that they might encounter in the future. I also remember that he's given useful replies when I've previously asked him about the x-risk reduction landscape in Germany.

LessWrong needs critics, and also needs basic kindness norms. In light of that, it seems that all that needed to be said about Alexander breaking the vicious cycle was "Good".