A/N: So I hated the whole Elizabeth plot this season and the fact that we are left to believe that she is actually Chuck's mother. But the part that bothered me the most was that it made Bart look like a total monster and destroyed everything we had learned about his and Chuck's relationship. I couldn't wrap my head around why Bart would 'hate' Chuck if he didn't actually kill his mother. Then I was reading something and I had this sort of epiphany and I got this insight into Bart's character that might be false, but I like this explanation. So it makes me feel better if they ever decided to go back to the Evelyn/Elizabeth plot on the show (which I hope they don't).
You might wonder just how cold and heartless Bart Bass really was. Sure, he wasn't the first man to keep his son from his mother, but he would venture to bet that he was one of the few, if not the only, to make that son believe he had actually killed his mother.
But, you see, in Bart's eyes Evelyn Bass did die in childbirth. The Evelyn who wanted a child, who wanted a family, who wanted Bart, changed so completely after their son was born that she might as well have died. Bart could place the blame on Chuck for his mother's death because in a way he did kill her.
After his birth, Evelyn became a different person, a person who didn't want all of the things she thought she had always dreamed of. Chuck's arrival caused Bart to lose the love of his life, whether she had actually stopped breathing or not, and for that Bart always unconsciously held a grudge against his son.
Bart never actually told Chuck that Evelyn had been killed in childbirth. But when Bart told his son that his mother had died when he was born, young Chuck couldn't help but read more into his words and Bart did nothing to correct him.
Maybe that made him a bad father. Maybe it made him the worst father in history. Because he did, in fact, blame his son. He did wish he could go back and never have his son if it meant he could keep Evelyn, the old Evelyn, the Evelyn that loved him. But he also did what he did for Chuck's best interest. If Bart was going to hate him regardless, better the kid think his mother had died than think that she simply hadn't wanted him. Better he believe he actually, literally killed her than know that he had killed her spirit, that she had taken one look at him and decided that motherhood, that marriage, that Bart, and that Chuck himself weren't for her.
Yes, he actually did his son a favor. Better he never know Evelyn at all then know the heartbreak that inevitably came in her wake.