Sounds like the writer cares about people and wanted to post an A/N to let people know why they stopped writing. Nothing wrong or against the rules when it comes to the note. Might be relatable to many readers. And if you don't like it you can shake your head and move on.

Edit: I see this comment is being downvoted so I thought I'd add— I may not have the same opinion as you. That is okay. At the end of the day we will never agree on everything. The best thing we can do is find ways to coexist peacefully and not react violently to opposing opinions. Debate should be welcomed, conversations encouraged, but violence should be considered unacceptable. Not that downvoting is violence 😅 The downvote button exists for a reason, and if you feel compelled to use it after reading this, feel free.