That's kinda the point though - the argument being presented is AFAICT "people who aren't that serious about it should still not be randomly outed."

I'm not convinced that's practically tenable these days, but on a moral basis I endorse it and would present Scott Alexander as an example of why.

Okay, but Scott actually had a reasonable argument for why the level of anonymity he wanted was important. Scott was not trying to start a conversation, Scott was trying to be anonymous. That's why he's such a good example.