She is motivated by money. She divorced me when my earning power seemed unable to support her stay-at-home mom fantasy. She was a 10 - 20 hour a week worker. But she wanted me to return to the corporate machine, and I wanted to negotiate an alternate route.
Even though it can be difficult at times, continuing my role as a supportive and cooperative partner is in the best interest of my kids. It's really in the best interest for me as well. A happy ex-wife is much better than an angry one.