Great question and I have to say with today's divorce rate at 52% and continuing to rise, it really isn't. People talk about the sanctity of marriage and the funny thing is these are usually the same people who have been married and divorced a few times. A couple who isn't married. they live together but love each other and stay together for the rest of their lives is much more meaningful to me than a couple with a piece of paper who then wind up getting divorced or stay together just because their religion and the piece of paper tell them to.
Marriage, in ancient times, was a necessary tradition because it protected the woman and her children so that way men couldn't just up and leave them. In today's world, it is not as necessary since most women are making even MORE money than their men.
And a lot of marriages I know take place because of the desire to have the big blow out party wedding. But you know that whole pesky till death do us part thing, well that's just a small little detail they seem to forget especially when they got their divorce lawyers on speed dial.