All the women who were involved except Alicorn, and at least one of the guys who started it have since left LessWrong, or changed their usernames.

False. Some of them comment less frequently, and I was worried myself for a time, but the people you refer to continue to comment here.

And SilasBarta has been picking on Alicorn ever since.

No. Just, no. I have refuted arguments she's made that I have found in error, sometimes harshly. I have applauded points she's made. I have come to her defense, even in contravention of my own interests.

I've never "picked on" Alicorn; she just has a tendency to completely misinterpret what I say or take refutations too personally.