I wish I had a line in my CV for every time I’ve heard reputedly intelligent persons – sometimes even ethical theorists -- dismiss moral realism with the line, “Who gets to say what’s moral?”
What does a person have to believe to consider such a trite remark a crushing rejoinder? Maybe the argument would run something like this: (1) There are no universally true moral precepts. (2) Or if there are, they are so mysterious that no one can be expected to know them. (3) Therefore you shouldn’t impose your moral precepts on me. (4) Proposition 3 is a universally true moral precept, and you ought to know it. (5) So I get to impose it on you.
Or maybe like this: (1) If anything were really right or really wrong, I wouldn’t like it. (2) Therefore nothing is really right or really wrong. (3) And it’s really wrong to think that anything really is.