1) claims that morality isn't arbitrary and we can make definitive statements about it
That isn't non-relativism. Subjectivism is the claim that the truth of moral statements varies with the person making them. That is compatible with the claim that they are non-arbitrary, since they may be fixed by features of persons that they cannot change, and which can be objectively discovered. It isn't a particularly strong version of subjectivism, though.
2) Also claims no universally compelling arguments.
That is;'t non-realism. Non-realism means that there are no arguments or evidence that will compel suitably equipped and motivated agents.
The confusion is resolved by realizing that he defines the words "moral" and "good" as roughly equivalent to human CEV.
The CEV of individual humans, or humanity? You have been ambiguous about an important subject EY is also ambiguous about.
I'm ambiguous about it because I'm describing EY's usage of the word, and he's been ambiguous about it.
I typically adapt my usage to the person who I'm talking to, but the way that I typically define "good" in my own head is: "The subset of my preferences which do not in any way reference myself as a person"...or in other words, the behavior which I would prefer if I cared about everyone equally (If I was not selfish and didn't prefer my in-group).
Under my usage, different people can have different conceptions of good. "Good" ...
There seems to be a widespread impression that the metaethics sequence was not very successful as an explanation of Eliezer Yudkowsky's views. It even says so on the wiki. And frankly, I'm puzzled by this... hence the "apparently" in this post's title. When I read the metaethics sequence, it seemed to make perfect sense to me. I can think of a couple things that may have made me different from the average OB/LW reader in this regard: