I didn't watch but one episode because you are right, it was a trainwreck and very sad... I have a hard time watching anyone drunk or on drugs and she was obviously on something.
It had all the entertainment value of watching someone drown while you stood on the sidelines holding tight to the life preserver. I was absolutely disgusted. However, it seems there were millions that enjoyed it. I think she was horribly wrong in her lifestyle and did damage to her own son and others that loved her, but we also failed her. This is an American tragedy. What can we do to prevent this in the future?