The tooth fairy example gets a variety of responses
Seriously? I've never heard anyone insist that the tooth fairy really exists (in the form of their mother). It would seem most contrary to common usage (in my community, at least) to use 'Tooth Fairy' to denote "whoever replaced the tooth under my pillow with a coin". The magical element is (in my experience) treated as essential to the term and not a mere "connotation".
I've heard of the saying you mention, but I think you misunderstand people when you interpret it literally. My response was not intended as some "peculiar" declaration of mind-independent meaning facts, but rather as a straightforward interpretation of what people who utter such claims have in mind when they do so. (Ask them, "Do you mean that the tooth fairy exists?" and I expect the response, "No, silly, I just mean that my mother is responsible for the coin under my pillow.")
So, to clarify: I don't think that there are free-floating "meaning" facts out there independently of our linguistic dispositions. I just dispute whether your definitions adequately capture the things that most people really care about (i.e. treat as essential) when using the terms in question.
It's no excuse to say that metaethical reductionism "gets reality right" when the whole dispute is instead over whether they have accommodated (or rather eliminated) some concept of which we have a pre-theoretic grasp. Compare the theological reductionist thesis that "God is love". Love exists, therefore God exists, voila! If someone pointed out that this view is needlessly misleading since love is not what most people mean to be talking about when they speak of 'God' (and it would be more honest to just admit one's atheism), it would be no response to give a lecture about constellations and tinkerbell.
I just dispute whether your definitions adequately capture the things that most people really care about (i.e. treat as essential) when using the terms in question.
It's no excuse to say that metaethical reductionism "gets reality right" when the whole dispute is instead over whether they have accommodated (or rather eliminated) some concept of which we have a pre-theoretic grasp.
What if metaethical reductionism is not meant (by some) to accommodate the pre-theoretic grasp of "morality" of most people, but just to accommodate the pre-...
In You Provably Can't Trust Yourself, Eliezer tried to figured out why his audience didn't understand his meta-ethics sequence even after they had followed him through philosophy of language and quantum physics. Meta-ethics is my specialty, and I can't figure out what Eliezer's meta-ethical position is. And at least at this point, professionals like Robin Hanson and Toby Ord couldn't figure it out, either.
Part of the problem is that because Eliezer has gotten little value from professional philosophy, he writes about morality in a highly idiosyncratic way, using terms that would require reading hundreds of posts to understand. I might understand Eliezer's meta-ethics better if he would just cough up his positions on standard meta-ethical debates like cognitivism, motivation, the sources of normativity, moral epistemology, and so on. Nick Beckstead recently told me he thinks Eliezer's meta-ethical views are similar to those of Michael Smith, but I'm not seeing it.
If you think you can help me (and others) understand Eliezer's meta-ethical theory, please leave a comment!
Update: This comment by Richard Chappell made sense of Eliezer's meta-ethics for me.