I can see it from both sides. Julie had the choice to sell the house, keep the family together and start again, or to basically send jimmy to jail. She chose to divorce and it was luck that Caleb bought them out and jimmy avoided jail. From jimmys perspective this proves that Julie was only in the marriage for money and would bail on him and take the kids as soon as he couldn’t provide that affluent lifestyle.

That’s after years of buying ponies and jewellery not for himself as Kirsten says. I think it’s pretty easy to understand how jimmy would feel mounting resentment in the first place and then betrayal once she divorced him. He also probably partially resents her for when Caleb blackmailed Marissa to live with them, even though that’s not directly Julie’s fault.

That said he is still a garbage father for abandoning Marissa multiple times.