Societal decay, decay of moral and values through a century of social engeneering.

A strong family is harder to break then an individual which can become a problem to ruling centralised power structures, whatever they may be

I think that is because now people are more free minded.

people dont take as much shit as before

and now more than ever, it is easier to find a new partner

Because they don't have to

Multiple issues as noted below. Want to add:couples are led to believe they should focus only on the kids. All the love is poured out to the kids and none is left to care for each other. They end up not loving each other when the kids leave-they feel trapped with some stranger when the kids go to college.

an increased focus on the individual perspective, wants, & desires

No fault divorce and the death of religion seem to play a major role, social programs and judges that blindly award 50% to the wife too, and sleeping around before marriage might have something to do with it.