Why was it awful?

Imagine the book, 600 or so pages. Hefty by anyone's standards.

Now pretend that book isn't a book but a historical fanfic that's maybe 25,000 words in length. Cut out the fact that it's from Mary's point of view and eliminate Stafford from the equation until the last two minutes of the film.

Have Henry VIII rape Anne Boleyn before Katherine of Aragon's preliminary hearing. Oh, and he's not a red-head either.

And you get the movie.