I may take some heat for this, but in my opinion, part of the blame can go to our litigious society that absolutely screws men in divorce cases. Sometimes, I guess, maybe they (the men that resort to murder) think the slight chance of getting awy with it is better than the very good chance of paying $1000 a week in child support, watching a new "honey" move into the house you built with your own two hands, sleeping in your bed, eating in your Lazy Boy, acting as if he's your kids' dad, etc.
In many cases, even when the wife is the one screwing around the husband gets screwed in the end.
Disclaimer: I'm not blaming women. I'm blaming lawyers.