Or perhaps it is, but so what? In a country full of wonks who spend their entire working day pretending that political actors are motivated by good arguments and statistics rather than prejudice and gamesmanship, the effort involved in employing the correct titles and forms of address for British peers and royals should not exceed anyone’s tedium quota.
Here’s how and how not to refer in everyday third person to the late Lady Thatcher and the Duke and Duchess of Cambridge:
“Lady Thatcher” or “Margaret Hilda Thatcher, Baroness Thatcher” or plain old “Mrs. Thatcher” (as Frank Field always called her); but not “Baroness Thatcher” or (ugh!) “Dame Thatcher” (a lesser honor, to say the least.)
“The Duke and Duchess of Cambridge” or “Prince William, Duke of Cambridge” and “Catherine, Duchess of Cambridge” or even “Will and Kate”; but not “Prince William and Duchess Catherine.”
Please consult Debrett’s with further questions.