Jews achieve acceptance in gentile society by renouncing their Jewishness, by declaring themselves to be Jewish exceptions, not like the 'other' Jews. That acceptance and that renunciation are especially true for the Jewish leadership. In exile, Jewish leadership is structurally disconnected from the Jewish followership. In exile, Jewish leadership must, in some sense, betray its own people.
Hadassah called herself Esther, and Mordechai also changed his name to an exilic version in order the gain acceptance in the Persian court.