All the above. Too many grow up no longer having good working models to base marriage on. Too many enter into it with the understanding that I'm here as long as "my needs are met". Too many believe marriage is a 50/50 proposition. Too many are no longer willing to honor promises encapsulated within the standard vows. Far too many enter into marriage to get divorced and whatever financial assets they can take from their partners. Also, as Mrs B recently posted, too many believe they can "love their partners through the red flags".