Why?

I mean, care to clarify?

Well, because there really isn't any originality to it. You're writing a novelization of a movie that's already been made. It's like remaking Bambi...which would be idiotic. I just don't feel the same about movie tie-in's as I do about an original novel, or even a shared world novel.
Take the Star Wars stuff. Those aren't based on the movies, not really. They're based on Lucas' universe and take place at different times with the same or different characters. They contribute to the universe because they add new events and depth to things. A movie tie-in is just giving you a literary presentation of the movie...i.e. it's like taking the script and fiddling with it until it goes from script to novel.
Just not the same.

I see...

Seuooooo...what do you think is the boundary is, or when do you believe the movie becomes worse than the book?

As soon as it poorly translates the book to the film...that's when...

So...if the movie is a good translation of the book, it's okay, right?

When does it become a poor translation. Does the movie have to deviate from the plot?

Best example of this would be I Am Legend.

I Am Legend, was a great book. It took you in and made you feel like you really were trapped in a world full of vampire-zombies.
The characterization was incredible, and the story itself was the first of its kind.
The movie, however, changed around everything that was great about the book and just stamped the title on a Will Smith movie.
Not that it was bad, mind you, but that it was not nearly as good as the book.

Just throwing in my two cents.

Well, I really enjoyed I Am Legend and think it to be one of the best films of last year, but it wasn't I Am Legend. They simply could have called it some other title and said it was based loosely on the book, because it isn't really like the book at all. It was a movie that showed how truly talented Will Smith really is.

My thoughts exactly, Shaun.

Will Smith really did deliver a great performance.
And the movie itself was good, but it still wasn't Matheson's, I Am Legend.

Shaun was a little disappointed when I didn't put I Am Legend on the poll for top movies of the year thread

But as for the book, after the movie I began hearing very good things about the book so I might want to check it out soon.

That's true. It's not Matheson at all. I've not read the book, but I've read about it enough to know that the movie deviated a lot. The best thing they could have done for the film to make it please both parties was to call it "The Cricken Pandemic" or something like that and then put in the credits that it was based on the ideas presented within Matheson's book. Then we would have known that it wasn't the same as his book, but still took things from it. I Am Legend is certainly in the top 3 of my favorite Will Smith movies. He's always sort of been this goofy action hero guy, and after this it's just impossible not to see that he is by far one of the greatest actors of our time. I mean, when the dog, Sam, dies, and he goes into the video store and talks to the mannequin saying that he promised a friend he would say hello...that just tore me up. You could see the anguish, the utter pain and torment inside him. Can you imagine losing the only person in the whole world that meant anything to you knowing that there was no replacement. You couldn't find another friend, that was it. I could see that in his face and any actor that can actually tear me up inside with their visual presence deserves a freaking award. If he doesn't get nominated next year I'll be seriously pissed off.