As Dalrock states,
a man actually loses protection from cuckolding and is placed at a disadvantage regarding custody if he marries. The only potential benefit a man gains by marrying is the moral force the marriage vows hold on his wife.And as there's no longer any real material incentive behind the "moral force," (or really any moral incentive as I explained above) it's a really shaky thing to base your life on. The only thing holding a woman back is if other women shame and ostracize her. Which is less likely to happen nowadays and even if it does, she can always shop for friends who will agree with her.
Women don't seem to understand this. They don't realize the potential life-destroying problems a man could suffer if the wife doesn't feel "satisfied" or "happy" in the relationship. It's totally unbalanced and totally unfair. Unrestrained female choice completely supported on the backs of men.
Women seem to live in this fantasy world when it comes to marriage. They don't want to think about what'll happen if it goes bad, preferring to keep it all mysterious. I guess they don't really have an incentive to do so anymore.