My comment said absolutely zero about the extent to which I think CEV is possible.

That's sort of like saying the internal combustion engine is an extremely crude attempt at a perpetual motion machine.

I don't think this analogy get's the levels of analysis of these two things right or accurately conveys my position on them. When I said normative theory was a extremely crude attempt at coherent extrapolated volition I was definitely not saying that all moral philosophy until now was a footnote to Eliezer Yudkowsky, or anything like that. I was not comparing normative theory with the theory of CEV. I was comparing moral theorizing to the actual act of determining the coherent extrapolated volition of a group of people. CEV isn't a normative theory, it's much more like a theory for how to find the correct normative theory (in the tradition of reflective equilibrium or, say, Habermasian discourse ethics). When people do normative theory on their own they are making extremely crude attempts at the ideals of the above.

I can see why you disagree w/ grandparent, but please note that CEV isn't supposed to be a grand new ethical theory. Somewhere in the background of 'why do CEV rather than something else' is a metaethical theory most closely akin to analytic descriptivism / moral functionalism - arguably somewhat new in the details, arguably not all that new, but at any rate the moral cognitivism part is not what CEV itself is really about. The main content of CEV looks like reflective equilibrium or a half-dozen other prior ethical theories and is meant to be right, not new.