When George Orwell sent Animal Farm to TS Eliot for consideration, the poet – then a director of Faber and Faber – rejected it, saying he remained unconvinced by the "Trotskyite" politics which underpin the book's narrative. Time of course proved TS Eliot wrong – but we'll never know how many masterpieces didn't get to see the light of day due to a publishers' lack of vision.
On the other hand, maybe there are some books that should never have made it into print in the first place. Imagine you're a powerful editor working for a prestigious publisher. Write a short letter to a (now) famous writer explaining why his or her work needs a redraft, or binning.