They are overgrown children, in other words -- not adults in any real sense of the word. It is an oddity about modern Americans that always strikes me: many seem so...unformed. I've seen pictures of my grandfather and grandmother when they were in their early 20's (married and with 2 kids already, and another on the way) and they seemed like fully-formed adults already. They looked like adults; they dressed like adults; they behaved as adults. Yet now I see people at 30, 40, 50 years old who seem little more than self-obsessed adolescents -- smug, directionless, angry but inchoate, lavishly educated but not particularly intelligent, entitled without being industrious or deserving. They even groom and dress like children: slovenly, unwashed, unbarbered, sneakers, t-shirts, sweatpants, looking like unmade beds. I look at the OWS protests and I see a crowd of ill-behaved, unsupervised toddlers, but no adults willing (or perhaps able) to call them to order. My grandparents had much more difficult lives in any way you can measure than these spoiled brats, and yet they were better people -- and happier people, on the whole.
My old man used to comment that if you went to an NHL game in the 1960s in St. Louis (when the Blues were the hottest ticket in town at the ancient Arena) nearly every man you'd see was wearing a coat and tie. The same was often true for baseball games, except in the bleachers. Men used to dress like men, and if you were in your late-20s you were expected to have spent some time in the Army and be out and have a real job and a wife and some little kids and a house... you were expected to be a grown-up, in other words. Now we let young men stay boys for decades, until it's too late to actually turn them into men.
If I had one thing to blame for this unfortunate trend, it would be birth control. Men become civilized when women civilize them with marriage at a young age, and women were able to exercise this civilizing power in past generations by withholding sex without marriage. But with the advent of birth control, women lost that leverage. Now, if what you read is true, young women are universally available, even for young men who ought to be thought of as "losers." In fact, I'd argue that the availability of sex is likely what turns a lot of young men into losers... they don't have to try hard to be a winner anymore.