Idk, from what I see, Chuck saw Jimmy as a lifelong screw-up and con artist and lazy. He always looked down on Jimmy and talked bad about him to other people. He never respected him, that's why he put him in the mail room at HHM, so he couldn't possibly mess anything up. Even Howard adopted that attitude towards Jimmy. Jimmy seeking Chuck's approval and always getting his disrespect because Chuck always viewed him as lazy definitely was his motivation to become Saul. He and Kim being responsible for the dismantling HHM was like a big F U to Chuck, who was an arrogant lawyer who would never think that was possible. Jimmy was so proud of that, no matter the cost, but it was much more personal to Jimmy. Chuck viewed him as someone who would do slimy things and bend the law to the advantage of undeserving people, and he was right. However, through this journey, the writers made it ambiguous about who is actually doing "good" as a lawyer, so Jimmy doesn't seem to be any different type of lawyer than Chuck or Howard. It got to the point where Kim was even dissatisfied with what she was doing with HHM.
