The Uncoolness of Marriage

When did it become a symbol of ultimate coolness to not get married?  I'm not talking about staying single and not getting married, I'm talking about having a "significant other" and not marrying them.  This arrangement is all fine and dandy with me - however you want to set up your household is no one else's bees wax in my opinion.
But, and this is a big but, why do people like Goldie Hawn get a standing ovation on Oprah for not marrying their "life partner"?  Why is this so commendable?  I don't get it.  It's like getting a standing ovation for renting a house instead of buying one...either way, you've got a place a live, have similar responsibilities, renting just must work better for you.
So why does non-marriage encourage responses like "good for you" and "that's awesome."  What is awesome about it?  Does the awesomeness come from the idea that you are more in love because you never let "the man" determine your relationship status? (I'm not sure if the man is God, the marriage licence office employee, society in general, a church, Justice of the Peace, or who - this is treading into waters that are a little too murky for me)  Or does the awesomeness come from the idea that you love each other less - you're free to fly the coop whenever, etc?  I'm not sure.  I am literally bewildered by what makes not getting married to your "partner", "lover", or "friend" cool.   
P.S. I bet that if Goldie decided to finally tie the knot with Kurt Russell and announced it on Oprah this week, she would get a standing ovation for that.