Well I suppose you have to put everything down to Digger's drunkenness and bitterness - all the hate flows from them and poisoned his and his families' minds.
Ellie chose Jock over Digger because Southfork needed saving and Digger was a drunk and wasted all his money = he blamed Jock for everything, never for one second taking any self accountability.
Later, when Cliff came along digger brainwashed him to his truth not THE truth.
Rebecca was most definitely the worst woman ever to be seen in Dallas. She left her children with a murdering drunk, slept her way to money, lied to her daughter's face about being her mum, bought her money obsessed son before dumping him and then bought him again. Then after having him nearly die she pushes him into a further battle with J.R when she could have dealt with him herself.
Cliff started off as a character who just wanted his daddy to have what he thought he deserved,but his hate and loathing for the Ewings just saw no bounds. He would be down and beaten but still pushed on, not least when he blackmailed Sly to get Ewing Oil info. Yes J.R did bad things to cliff and warned him over and over again not to cross him, but Cliff was like a lemming....he just couldn't stop himself and eventually turned from a wonderful, fully rounded character into a man with not many redeeming features at all. I won't even mention TNT because that was NOT Cliff Barnes.
Pam was OK - thought she was a bit of a cow to leave Bobby and taking her son, flying around Europe with Mark Grayson and then getting all funny about what Bobby was up to with katherine. I also really didn't like it when she gave out to Bobby when she was doing far worse and couldn't see it.
And then Katherine....basically forgotten by her own mother, walked over by Cliff and Pam, and then Pam and Cliff, who her mother has only known for a year or so take away most of her money, property and businesses. It's no wonder she went a bit ming mong really is it.
But all the troubles with the Barnes lay with Digger & Rebecca...the buck stops with them for lying about their pasts and not owning their mistakes.