That would be editorialising, since that's in the actual article.

> Otherwise please use the original title, unless it is misleading or linkbait; don't editorialize. https://news.ycombinator.com/newsguidelines.html

Edit: I don't mind being downvoted, but I would really like to know why that's the case so I can improve how I contribute to the forum.

For the most part it's correct, they emded the experiment. However, it would probably communicate better to say "Then had to turn back." That probably conveys what happened, in that the "bad" stuff that we attribute to the algorithm still managed to grow without it, and normal engagement went down.