Yet the noble Chuck McGill can't bring himself to tell Jimmy that their mother's dying words were for Jimmy. He took that to his grave, effectively destroying himself in his efforts to destroy his brother. Tragic, yes. But whatever sympathies I find for Chuck are tempered by having insights into his temperament and motivations. He's passive aggressive, self-centered, and not particularly self-aware. Of course, it doesn't help that his brother's a high-functioning sociopath... that'd probably drive anybody crazy after a while.
I don't know that we'll ever find out more details about the stalemate between Howard and Chuck, but there are certainly elements of extortion ("give me my way or I'll bankrupt the firm that you and your father built") in their relationship. I wouldn't attribute that sort of behavior to a nice guy.