Are we talking about "Evolved Men" or men in general?
In fact, we're not supposed to be talking about men at all.
I challenged the Man Up promoters to define what they consider to be the characteristics of a "proper" or "correct" woman. The analog to Strong, Masculine, etc.
So far, not so many takers. Because it's dangerous, you see? Who wants to step up and say, "Ladies, your husbands left you because you're not "woman" enough?"
Not me, brother. But note that such a sentence would be, by symmetry, the perfect analog to "Gents, your wives left you because you weren't man enough." Which is, let's face it, the Cliff's Notes version of the story promoted by the Man Up crowd.
I'll take that challenge ;-) - working from home today so give me a few minutes and I'll come up with a few honest reasons why men would leave their women. In an online forum where anonymity is a given, I think we can all afford to be blatantly honest.
Honesty, good trait for any man to have - being honest means you have courage.