Not all, but many wrecks of books include the authors imprimatur on the uplift to live actors. "yea, I know its hard to do a skeleton, lets make death be an actor with a black hood" is low bar. "No, the lead didn't get to sleep with the other lead in the book, but what the hell, put a sex scene in episode 3" is medium bar. "I changed the ending for you, if you need more changes just let me know for $" is high bar. Actually, they're all low bar.

Even Margaret Atwood says she willingly works with the production company to "make it work" on screen. Plot evaporates in an instant.

As you say, and I agree: its not a sacred text. Speaking of which, I think TV novela versions of sacred texts usually wind up where 'hail ceaser' went: a committee of wise men (and it always is men) arguing about whats sacred anyway..