I am not sure I get your point. A consensus of author and protagonist is just one option and not the most often used one at the theatre or in, well, what is often called “high literature”. The narrative stance of an author can be affirmative towards his main or any other protagonist (or antagonist), but it can also be critical, adverse, euphemistic, ironical, sarcastic or neutral.
Molière and other playwriters of comedies have often used protagonists that show outrageous mind sets and behaviour; the beliefs of the character Michael Kohlhaas in the drama of the same name are politically in accordance with Kleist’s but his behaviour reveals a critical distance towards the consequences of the protagonist’s obsessive rightfulness. The Marquis de Posa in Schiller’s Don Carlos is the author’s mouthpiece – and yet, he fails miserably.
Thomas Mann is certainly at odds in Doctor Faustus with the protagonist as well as the narrator; old father Briest in Fontane’s Effi Briest speaks for the author, but he isn’t more than a marginal figure – and his passivity shows a self-deprecating stance of the author.
Dostoyevsky and other Russian authors also showed very complex stances towards their protagonists – just think about The Brothers Karamazov, especially Book 5: “The Grand Inquisitor”.
If you want examples of a full-blown adversial stance, there are plenty too.
Heinrich Mann’s Der Untertan (The Loyal Subject or Man of Straw) is a condemnation of the Kaiserreich. His protagonist, Diederich Hessling, is a creep.
Günter Grass’ story *1934 *is an inner monologue of a SS-henchman, who tells us his point of view of the murder of the jewish author Erich Mühsam in Oranienburg.
Brecht’s Der aufhaltsame Aufstieg des Arturo Ui (The Resistible Rise of Arturo Ui) is a parable about Hitler’s way to power set in the milieu of criminals. Not surprisingly, Ui is not Brecht’s political mouthpiece.
A ton of works that deal with oppressive regimes and are told from the perspective of one of its proponents are anything but propaganda material.