So then Moore's law should be faster than Yudkowsky's analysis predicts, because of cultural evolution? I still have no idea what you're trying to argue.

It seems to me that timtyler's point is that Yudkowsky is wrong to claim that the current Moore's law was extrapolated from fix-speed engineers. Engineers were ALREADY using computers to enhance their productivity, and timtyler suggests that cultural factors also increase the engineers speed. The cycle of build faster computer -> increase engineering productivity -> build even faster computer -> increase engineering productivity even more, etc was already cooked in to the extrapolation, so there is no reason to assume we'll break above it.