appropriate lore question in the appropriate lore general

So Lorgar was actually really successful in making the handful of his great crusade conquests into emperor worshiping utopias. It's the main reason the emperor actually bothered to jump in and bomb monarchia. Too much quality not enough quantity.

So when the Lectitio Divinitatus eventually falls into loyalist hands post heresy and becomes the foundation of the imperial cult. Everything goes to shit and the great religious dogma that got slow but quality results becomes the oppressive religious dogma that 40k is known for.

What happened? Shouldn't a perfect copy get the same results? Who was the jackass that copied wrong and where?