Thanks a lot for working on Arbital, and thanks for this writeup. It is always great to know how such projects went, why they stopped, etc…
Being one of the people having expressed an interest in an open source Arbital, I am trhilled to hear it might still happen!
I think experimental moral psychology puts a bunch of holes in this notion the moral category is a recent one, as studies of people like Jonathan Haidt seem to show that morality is pre-wired in human brains and may have been a crucial step in our biological evolution.
Do you have examples? Each time I heard concrete examples of those supposedly numerous things, they were things they weren't glaringly obvious at all.
Also, as a rationalist, knowing that it's glaringly obvious to any person looking up each day that the Sun goes around the earth, and that, last I checked, this glaringly obvious belief is shared by 1/6th of the French, 1/4th of the Americans and 1/3rd of the Russians, I am exceptionally wary of anything supposedly obvious.