Excellent observation Phy, and an extremely valid question. I think the unresolved negative events in their marriage absolutely play into the issues that are impacting them now. All three of them are acutely aware of it and with the awareness come the responsibility to take action to address the issue rather than holding on to the resentment like a worn out security blanket. Furthermore, some of the basis for Maca's negativity and the love/hate dynamic goes further back than his marriage to LR. He's aware of the impact of these unresolved past events too. He knows the steps necessary for moving towards improving his relationship(s) in general. But knowing the path we need to take is not the same as standing up and walking it.
"Life is too short to always sit around worrying about the bad shit that could happen. It's a lot more fun to go start some shit of my own. "