I am the walkaway spouse. My stbx is 31 years old and is not going to change. She has had several chances, including counseling sessions (individual/joint) and also a BIG chance to figure out if she'd rather pursue her hobbies or be a wife after I moved out (the first time) last summer. She chose to be a wife for two months after we moved back under the same roof; once again her friends and hobbies are coming first while I'm the one taking care of the kids in the evenings (while paying all the bills on my income). I give up. Life is too short for this nonsense, and I have chosen to retain what is left of my life and make it happy while hopefully making others' lives better.
Am using "new free time" that I'll find after the divorce is final as a way to contribute to charity, make elderly folks' lives better, maybe work with Big Brothers/Big Sisters, etc.