On a personal level I would say that marriage is more than just a piece of paper. Jess and I were together for nine years before we got married. The reason I asked her was because I was ready to take the relationship to the next level.
Whereas before I insisted on birth control now I want a kid. Whereas before I insisted on separate bank accounts now we have a joint account. Whereas before I wasn't quite on board with the one woman for life thing now I wouldn't have it any other way. To me the act of getting married was more than having a great party or getting that piece of paper... It was about publically declaring my commitment to her.
These public declarations are important: are you more or less likely to stay on track with your goals after you've told people about them or not?
Lots of people don't take this commitment seriously... They think it is just words you say. But you see that trend everywhere. Oaths are just words not something meaningful and important. For us it was the opposite. You don't say those words in front of a couple hundred family members and friends unless you take it seriously. I asked her dad for his blessing - there is no way I'll make a fool out of him and myself by reneging on that commitment because things get tough.
I mention this because the real problem is that people view relationships as disposible. You get what you can out of them and when it becomes hard you just end them. The idea that you should struggle and maybe even learn from those struggles is dead. I don't know why this has come about but it seems to apply to all relationships not just romantic ones. People abandon their kids. Their best friends. Their family members. All because sometimes it is hard. The moment you stop getting more than you give many decide it just isn't worth it.
Loyalty is an obsolete concept and it's destruction is having profound effects on our society. I'm not sure the government can do anything more than it already does. You can't force people to be loyal.