Yvain doesn't post to LW because he finds it too stressful. Partly this the stress of the watching the number after posting, but mainly the uncertainty ahead of time about whether his posts are good enough or appropriate.
Added: I was probably thinking of this comment, but it doesn't mention karma.
That seems analogous to the reasons EY stopped posting on LW, so maybe we can form a hypothesis about things that drive highly visible posts away from LW?
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.
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