This isn't about insincerity, it's simply a basic aspect of social behaviour. You don't sit on the bus crying or singing a happy song if you're sad or happy. We manage the emotions we project as second nature, just as we read and interpret the projected emotions of others. It's the opposite of sociopathic.
The rule should then be "don't berate others"
No, because the rule is about a specific (potentially) reflexive behaviour that can be destructive in the context they're talking about. They are trying to help people address it. "Don't berate others" is a fine sentiment but a little vague.
This would make sense if we were making an exhaustive list of "potentially reflexive behavior which people may engage in but should not in this community", but keeping such a list in your mind is one hell of a downer. The best rule to encompass this, I think, is "epower those around you". Noisebridge has an even broader social rule / ethos which has served them well: "be awesome to each other".
Love the community at Recurse, but having social rules be a list of shitty things someone once did is the least awesome part of Recurse :-)
Why would that make sense? It makes sense to point out common ones. Especially if you are, presumably like the people at Recurse are, informed by the experience of running that type of learning environment. They aren't trying to be exhaustive or all-encompassing or even a downer. They're trying to deal with problems they've encountered, not writing a formal system of acceptable behaviour.
> you can feign surprise at someone's ignorance not because you're really surprised but to berate them
On point! The rule should then be "don't berate others", or the more positive "empower others". This is just one example of this rule, one that I have not personally seen come up often, but perhaps that's because I have exactly 0 interest in being around anyone who berates others.