The quote below is from an article by Fr. Dwight Longenecker and can be found in its entirety here. The whole thing is worth reading.

Emotivists contend that words which suggest an objective morality like “good”, “bad”, “right”, “wrong”, “should”, “ought” have no basis in reality. They are merely the emotional expressions of the speaker and that he uses these words to bully someone else to do what he wants. It’s called “boo-hurrah” morality because the morality consists of nothing more than one person saying, “Hurrah! to this” or “Boo! to that.” Morality is thus reduced to “It’s right because I said so loudly” or “It’s wrong because I objected loudly.” Emotivism excludes social, historical, cultural, spiritual, and religious considerations from the discussion of morality.