In the past, Grandfather Ji was always supportive of whatever Yue Ling and Ji Jingxu wanted to do. However, ever since he found out he didn't have much time left, he started to become persistent with them.
It was also the reason why he kept pushing Yue Ling to take over Ji Corps. At first, he wanted to pass the company down to Ji Jingxu, but with the limited time he has now, he knows that he couldn't.
Ji Jingxu is still young and does not have enough strength to defend against Ji Chu Hua or any of the other people trying to take over the company. With this thought, he decided to pass the position down to Yue Ling. Even though she already has three other companies to take care of, he knows that she is the only person Ji Chu Hua and her father will never be able to take down.
When she agreed to take over the chairman position, he was indeed happy and at ease. However, despite feeling this way, a part of him could see through her true reason for accepting.