I think it's fair, principle of charity and all, to assume "babies" means "baby humans" specifically. A lot of things people say about babies becomes at best false, at worst profoundly incoherent, without this assumption.
But you're right of course, that there are many scenarios in which killing human babies leads to better solutions than not killing them. Every time I consider pointing this out when this question comes up, I decide that the phrase "inherently right" is trying to do some extra work here that somehow or other excludes these cases, though I can't really figure out how it is supposed to do that work, and it never seems likely that raising the question will get satisfying answers.
This seems like it might get back to the "terminal"/"instrumental" gulf, which is where I often part company with LW's thinking about values.
Yeah, these were just a couple examples. (I can also imagine feeling about babies the way I feel about mosquitos with malaria. Do I have an exceptionally good imagination? As the imagined feelings become more removed from reality, the examples must get more bizarre, but that is the way with counter-factuals.) But there being ready examples isn't the point. I am asked to consider that I have this value, and I can, there is no inherent contradiction.
Perhaps as you suggest, there is no p&-p contradiction because preserving the lives of babies is not a ter...
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: