I think people like the idea of marriage more than anything. Long term relationships always have ups and downs, you can never experience the good without the bad. Some people are just not settlers or not capable of sustaining a long healthy relationship,I'm not say it's a bad thing,we are who we are.so the construct of marriage and what it is meant to represent doesn't suit everyone.
I don't think divorce is a bad thing, sometimes it's for the best. Divorce can give closure too, just as some need the binding of marriage as a comfort, the divorce is just what they need to start a new chapter.