You can tell a lot about a man by the way he treats his children. I think Jock was a great man to have inspired the type of love and loyalty he did in Bobby and JR. He wasn't perfect when you consider Gary and how he never taught JR when to stop. But no human being is perfect and not being perfect doesn't mean he wasn't great. He had lots of good, loyal friends. He was a self made man who provided a valuable product with his business. He also saved Southfork from being auctioned off. You only need to look at Miss Ellie's reaction to his death after their over 40 years of marriage to realize she loved him dearly and missed him terribly. He also handled the situation of finding out Ray was his son in a great way and truly accepted Ray as his son.
It was upsetting to see Miss Ellie treat him so badly because of his accepting Ray into the family, to the point she almost divorced him after 43 years of marriage! He was very supportive and loving towards Miss Ellie,especially when she was going through her mastectomy. he went to the hospital constantly, barely sleeping, and yet she ignored him and treated Digger Barnes very warmly while she let Jock suffer, all because he had divorced Amanda. Then when she met Amanda she realized he had to divorce Amanda when he did, but she sure put him through hell over that and his accepting Ray into the family. She even threatened him, saying about Bobby possibly moving from Southfork into a home of his own with his wife "If I lose another son because of you I will never forgive you"! Lose another son? Bobby wasn't dying; he was moving to a home that he and his wife could call their own! How many mothers go through that and don't accuse their husbands of making them "lose" a son? What Bobby and Pam was about to do is actually very normal thing! So that was cruel and wrong. basically, she wanted Jock to keep Bobby at Southfork at any cost, even at taking JR's job away from him and giving it to his much younger Bobby who only had a small fraction of the experience and expertise in running an oil business that JR did. In fact, while Bobby had time for nothing but playing football and being a playboy, JR was working right by Jock's side, in the oil fields and in the office. JR was working right by Jock's side while Bobby was "sowing his wild oats." When Bobby finally did go to work for Ewing Oil he was what Jock once called "the company pimp." That consisted of handing out favors to influential people who could help Ewing Oil - hardly the same as working by Jock's side for 7 years running the company!
So while Jock had a few small flaws, he certainly had no more than Miss Ellie. He was a great man and Jim Davis did a wonderful job portraying him. It would have been terribly disrespectful to have replaced him after he died with another actor playing Jock so I'm very glad they didn't do that. I can't imagine anyone else playing that role. My favorite scene with Jock is when Bobby fights with Jock in front of his friends and complains about Jock taking money out of his own company without getting Bobby's permission! Jock stood up and proceeded to give the best performance he had given in the whole series as he told Bobby "So I gave you power. Well if I did give you power you've got nothing! Nobody gives you power. Real power is something you take"!