W has told me and several others (her mom, friends) that no house owned for 16 years, investments no where near where she thought they should be are the reasons - security.
She hit her limit for waiting. We did discuss it regularly and it was clear that is what she wanted but she didn't push it too hard. She seemed on board with our lifestyle choice.
She added a few other reasons such as when we fight (which was very rarely, every 1.5 to 2 years) that I would get withdrawn and not talk. That drove her nuts. I would explain that it was better than fighting in front of the kids. We worked out a plan that I would say what was bothering me and ask for a few hours to be quiet and then we would discuss when we were both calm.
M: 48 W: 45 Married: 16 years D1-14, D2-11, D3-9 BD: May 29 She moved out 2 weeks later with kids Awaiting mediation