I have to disagree with you on that one. These posts are also filled with stories of how being nice has changed the spouse's behavior. In fact, isn't that one of the principles of DB? Once you show a nicer and non-confrontational side, the spouse has no one else to get mad at and looks in at themselves.
Now whether or not they decide to continue with someone else or return is up to them. In my case, my W actually calmed down enough to come home.
Just establish boundaries of what you will and will not tolerate and live through that. Not all of the stories of Going Dark are gloom and doom. It just comes down to what you're willing to do to stay married and if that's what you really want.
M-43 W-40 2D - 9 and 5
Emotion, yet peace. Ignorance, yet knowledge. Passion, yet serenity. Chaos, yet harmony. Death, yet a new life.