I think humans have competing, conflicting interests and believe the evidence supports this scientifically. We may have some drives toward monogomy while having the desire to be free at the same time.
I don't think I'm cut out for a happy marriage. This partly my behavior and partially the kind of women I like. I enjoy the company of very independant women who enjoy partying and having a good old time. They don't really make good wives any more than I'd make a great father. This could change, but maybe not. In general I'm not good at compromise.
I think some people are much better cut out for long term relationships. I think there are benefits both ways. But the insitution of contractual marriage, rather than simple monogomy, is outdated and built on assumptions which no longer apply - namely that men and women have special rights and special priviledges not equal rights and equal entitlements. Both systems can work, but not an imbalance.
I'd like to see "family licenses" instead of "marriage licenses." These would be agreements to share assets and responsibilities for the purpose of raising one or more children. These agreements would expire when the children were 18. Beyond that, marriage is religious and I don't care who get's married or what they want to do about it.
I personally would never marry someone who didn't sign a pre-nup. I'm selfish and mistrustful. My mother, for example, joined a crazy cult after 10 years with my father. People change and I will not promise future sacrifice in the face of unknown future events.