what was wrong with the original ending?

when I first read the count of monte cristo I was blown away. To this day it is still one of my favorite books of all time. I have seen just about every adaptation of the book. I have one question? Why is it that no adaptation follows the original ending? I mean what is wrong with it? I had hoped based on the direction that the show was taking that it would follow the ending of the book. But in the end...i was let down again. I don't am I the only person who prefers the original ending?