Mine was because I would like to see fewer comments here that simply suggest "Read the sequences" without suggesting why.

I can understand that that could sometimes be a problem. But doesn't Eugine's quotation make it clear that he was pointing to where "EY has considered [morality] seriously"?

I guess I was surprised because I'm inclined to view this kind of cross referencing as valuable. For example, it makes it easier for lurkers to follow a chain of links back to substantive explanations in the sequences. But I take your point that "Read the sequences" is way too broad to be useful, and "read the metaethics sequence" is still very broad.

But, in this case, Costanza had possibly implied an interest in Eliezer's views on morality. And, until Costanza expresses a more particular interest, the best that you can do is to direct him/her to the entire metaethics sequence.