Wanted/Ballast, Now I am certainly no expert on any of this but I would say there are mental health issues to some degree in almost all sitch's on here. There appears to be a lot of depression, conflict avoidance, emotional immaturity etc.
The why. Isn't that the million dollar question? My W's reason, "I just don't want to be with you like that". That certainly narrows things down doesn't it. Again I think the why or lack of why is due to some of the mental and emotional health issues with our WAS's.