Why change Chivery's final inscription?

It was by far his best moment in the book, and it was quite perfect as it is. It showed that despite his continuing passion, his love didn't define him any more. Neither did his job. What mattered now were his charater and actions. I found it to be such a perfect ending for his character's story. What a shame that it was changed for the adaptation.



STRANGER!
RESPECT THE TOMB OF
JOHN CHIVERY, JUNIOR,
WHO DIED AT AN ADVANCED AGE
NOT NECESSARY TO MENTION.
HE ENCOUNTERED HIS RIVAL IN A DISTRESSED STATE,
AND FELT INCLINED
TO HAVE A ROUND WITH HIM;
BUT, FOR THE SAKE OF THE LOVED ONE,
CONQUERED THOSE FEELINGS OF BITTERNESS, AND BECAME
MAGNANIMOUS.