That people get married, and stay married, less, is not evidence of a lack of motivation to be committed, per se; it's evidence that society is moving away from the need for enforced commitment to begin with. People would rather be free.
I understand your point. To push against orthodox ideas would require an ability to think in an independent fashion. Usually a handful of people think independently, and then a bunch of people are like "oh cool, secret knowledge" and jumps on. Then it's no longer revolutionary - what it once represented starts being abused.
Civil Rights and Feminism - check out what that means in America. It started out as a pure walk for equality, but has been hijacked by a victim, entitled mentality... which ironically was what the opposite of what these movements fought for, which was independence and equality, NOT flipping tables, vengeance, and dominance.
America, in how the culture views values, issues and such, isn't like most other places. The no-fault laws and freedom to divorce is directly linked to Third Wave Feminism. Now, while I sympathize with freedom to get out of an abusive marriage or adulterous marriage, frivolous divorce or divorce because of two horrible matched to begin with people, is NOT good for children, historically.
Children often reported feeling they are responsible for the divorce, sometimes the parents use them as a means to guilt or take revenge on the other parent. Children suddenly have two homes, two addresses, two birthdays, two Christmases... if both parents are still involved in the child's life, the child is split in two and feels like being good to one parent is betraying the other. If one parent falls out of the picture, the sting of rejection plagues the child who is not old enough to understand.
It is not good on the psyche of a growing child that needs stability at that time in her/his life more than any other, while the brain is literally still growing and developing. The issue is in what marriage is still ideally held as, particularly in the Church, which is man and woman married for life (I'm not going to address the gay issue here.) Children watch fairy tale movies that depicts (unrealistically) that a relationship should be for life. They hear the words "forever yours" and "we'll always be together" in love songs, across genres. The expectation of a real love being solid and long-term still echos in our culture.
Now, divorce seems so commonplace (though I think there was a time in the late 90s that the rates leveled out), that MAYBE society will adjust to this (I doubt it)... if it doesn't collapse first. And that's a totally different animal, but when two people get married, they join in finances, if they have kids together they are both in custody and if things get ugly and they don't have a prenup, then depending on circumstances divorce can be long, drawn out, and nasty... with little kids in the middle of it all. I don't advocate staying together JUST for the kids, if a couple is just can't communicate constructively in front of the children or can not exist together in a healthy manner. But future children should, SHOULD be an incentive to be selective about who you do marry.
Again, this is America not Ireland. The climate socially here is very different, from my understanding of other places. My husband has been around the world, and said that in his experiences, the extremity of the American mind is unique. Still a very conservative country - at least by talk, even liberal people may have conservative sentiments like modesty for example - but the legal, social, and financial stuff tied into divorce makes it a detrimental thing to THIS society when it is a trend. I'm not saying just when it happens (cause it will) - I mean so commonplace that many go into marriage with a "let's see how it goes" attitude. If marriage wasn't so tied into politics and gov, it might be different in its effects.
But not just that, but the emotional implications of having a relationship in which there is no spoken commitment. The assertion "hey this is real" is important in this society. We have the "hook up" culture, and if both people don't make perfectly clear whether they are just playing around or serious about being an item, then there's lots of confusion that happens, heartbreak and maybe with a side of STI or pregnancy tests. The meaning behind the "it's complicated" as an option for a relationship status on FB.
Most people commitment means a ring. Some people will break up with their significant other because just living together doesn't indicate seriousness... because chances are she/he has lived with others in the past... so there's nothing there that says "This is different - we're not just living together, we're going to weather thick and thin." Maybe some are so confident in their love and devotion they don't have to declare it in any shape or form, but as I understand it, marriage is being avoided largely to be free from the legality of the union. Some people it's just a private nobody's business situation. Want to leave, unhappy, just pack and go. That's not commitment. At least not in my book.