Sorry if this offends anyone. This is not meant to be an indictment of James Earl Jones. But if we are being honest, Mufasa has some serious character flaws that cannot be overlooked.
He teaches his son and heir to the crown to be disrespectful towards their servants when he conducts a "pouncing lesson" on Zazu, against Zazu's wishes.
He doesn't discipline Simba AT ALL when he defies his father's wishes and takes his friend to the elephant graveyard.
He loses track of his son and allows him to wander into a ravine where the wildebeests are known to stampede frequently, then looks to his younger brother to get him out of the snafu he has created with his being such an irresponsible parent.
Here's the worst part: Scar gets his shot at being the king, and by sheer coincidence a famine ravages the Pride Lands. Scar has no control over the climate nor the weather patterns of sub-Saharan Africa, and yet he is fully blamed for the problems that arise because of it.
I'm a huge fan of The Lion King, but these issues have rubbed me the wrong way for a long time. Imo, Scar should have been given a second chance.