Thoughts On Marriage and It's Pointlessness (A Woman's Point of View)

I don't understand the women, or men to be fair, who tell you the reason they broke up with someone was because they weren't "willing to take their realationship to the next level and make a commitment." Only one thing comes to mind for me in this situation. "Why were you so selfish that you could't respect that they weren't going the same way as you in life at the same exact moment?" Why do people feel the need to get married after they've been together for a certain amount of time? Why can't they stay happy and content as they were or as they had been living? If the relationship is failing that's one thing but to break up with someone because they haven't asked you to marry them is ridiculous. I understand the American dream of many women's to walk down the aisle to the love of their life and have him or her commit themselves for eternity. But really, are people so insecure that they need a piece of paper to bind the person their with to themselves? If the person you're with is committed to you in your relationship then they will stay committed to you whether a piece of paper binds you or not. If the person you are with has cheated on you or has done you wrong, marrying them will not change them. They will still do all of the things that they have been doing. So why are the people of the United States so eager to walk down the aisle and spend ton's of money on something that will last all of 10 minutes at the most? This sounds so pessimistic but it's not. I just don't understand why people can't be happy without a piece of paper saying that they are bound to someone for life. Its most definitely not all it's cracked up to be anyways.