Especially crazy when Douglas Adams has a writing credit on the screenplay, and all indications are that he was substantially involved in it's contents.

Edit:

The script we shot was very much based on the last draft that Douglas wrote... All the substantive new ideas in the movie... are brand new Douglas ideas written especially for the movie by him... Douglas was always up for reinventing HHGG in each of its different incarnations and he knew that working harder on some character development and some of the key relationships was an integral part of turning HHGG into a movie.

- Robbie Stamp, Executive Producer

It's funny when people say that the original book was better. When the book itself is just an adaptation from the original radio play

While I have my nitpicks with the movie, overall I adore it. Especially Marvin's design