Y'all are talking about ten different things at once
I will focus on heterosexual marriages
So when the marriage falls apart, the less committed person gets advanced
The more committed person pays
When women are the more committed, they get a second shot at justice through the court system
Child support, alimony, the marital home, division of assets
Even though she "lost" emotionally, she can still win financially
Third way she can win is through trial of public opinion
Women can say some stuff to kill a fellows reputation.. And do it in a way that is "#facts"
Men aren't good at the telephone gossip game .. What he says is sour grapes
Men might be reduced to violence.. Not because men are more violent than women.. But because he can't "win" other ways
It is only a hypothesis.. No time to crunch data
Depending on the disparity of effort, the more committed person has already over-invested their money/reputation/time into the failed marriage
So the pressure to recoup is a big stressor
Leading to "winner take all " thinking