First off, Friends is a freaking old show that hails from the time when women were expected to desire marriage as the first priority in their lives, whether or not American wanted to admit it. Second, I twitch a whole lot at your "potential as males" statement.
You're basically saying that men are shallow and want to pork anything with big boobs and a pretty face, and that they're entitled to go around and do this throughout their 20s. For one, I don't believe anyone should want to even date a guy who acts like you said you do -- getting horribly distracted when a pretty girl walks by, wanting your complete freedom to go hook up with anyone, anywhere, anytime. This is what 16-year-old boys do. If you're 23, start growing up. This doesn't mean you have to think about marriage, but you should really be getting over the "omg boobies" phase now.
You're also telling people of my age (22) that we "don't know shit," a point with which I very much beg to differ. I very much know what I want and how I want it in terms of men and dating, and I'm pretty mature about it. I have a good job, a fun life, and am definitely looking for a guy to share that with me someday. Am I going to rush into it? No. Am I going to weed out my dating partners now based on my criteria for a serious long-term relationship? Yes. Will I be thrilled to find The One someday that isn't 10 years away? Most definitely, and whether he arrives in 1 year or 9, I will be totally happy about this. Marriage is something you do when it's the right time, whenever that is for you.
Why does America like it? I think for one, it's a statement of dedication and security. It is a symbol of assurance that neither party will leave the other. Now, this doesn't really mean anything to lots of people, but I believe that's why it's there. For people who are Christian, it's a promise before God that you're going to do everything in your power to stay together. For people who aren't, it can still be that kind of symbol, a professing before everyone there of the same. It means that you have a friend for life, someone who will consult you before they upend their lives and run off into the wild blue yonder, someone who will never leave you even if the entire world does. It's having a partner to go through life with, if you do it right.
I don't think that's such a bad deal. Also, if you don't have kids, you now have two people's income and one person's worth of things like housing payments and stuff.
I resent that "arcane superstitions" comment about my religion also. Let's not judge all of Christianity by the Conservative Right, shall we? I thought we were over that.