"Scott Alexander was demanding everyone else's assistance in maintaining his pseudonym and pretending the real identity behind it was unknowable."
Absolutely false. Scott admits many times that it's trivial for his real identity to be known if you search around for Scott Alexander.
Scott Alexander -> Scott Sisnick (trivial)
What Scott was concerned about what his searching his real name being resoundingly brought to Scott Alexander, a major issue for his psychiatrist-patient relationships, as he demonstrates that psychiatrists need to maintain a blank slate for their patients to project onto, so that the patients don't hide or alter the behavior knowing something about their psychiatrist. That's very mainstream psychiatry. And there were concerns about current psychiatric patients he was seeing possibly being affected by this.
Before: Scott Sisnick -> "psychiatrist, bay area, studied at X, etc."
After: Scott Sisnick -> "Scott Alexander, rationalist, providing a platform for white nationalists, racism, etc."