I do agree with part of what he is saying about being attractive to the wayward spouse. Building a life and GAL without them. Many of the reconciled spouses have said that a big factor was seeing the LBS moving on without them and that life would be 'okay' without them.
That was the point I was leaning towards.
Yep. That's spot-on, and it's basic human relationship dynamics. People tend to value most that which is difficult to obtain.