I see that women posters have a different view on marriage. I have the feeling that the comment about a man not being that into someone if he hasn't married her after some time deserves some comment.
Women would have it worse if they were left behind with a child. That is why so many want the legal and social obligations that come with the signing of the paper. The sad thing is that so many a man will not become responsible for kids unless there is some form of coercion, and women want that too. So they are more inclined to having the ceremonies. From a male perspective, let me assure you that the piece of paper is looking more and more like an inconvenience, and, therefore, so many do not marry if they manage to share the home with the woman. In their eyes, they already got what they want without the obligations.
Probably the women are also concerned about the status. Some men still make a difference between a woman they would marry (this being the "good one" and a woman they wouldn't. Naturally, a woman wants to be in the "good" group, and it's not just about status, but about determining how the man sees her.
And then, of course, women want to see a tangible "proof" of commitment. I think experience (and the good money divorce lawyers make) are proof of the opposite.
I believe that, in marriage, as in your membership in a religious organization, it should not be coercion or whatever is said through the grapevine that should keep you in. If I love the woman I live with, yes, I am willing to marry her, but that doesn't mean I NEED the piece of paper to do what's in her best interest.