The article seems to me a just-so story. The author might be ignorant of the rich kids who end up as drug addicts or at the very least entirely economically unproductive simply because they can. They've got nothing to loose by not kowtowing to the bosses but nothing to gain by working hard either as they've already got everything laid on a plate for them.

However I think there often is something different in the attitudes of people with rich and poor upbringings. But from the article the kid whose parents earn $125,000 and who was bright and went to a top tier school will likely have all the doors open to him and the self confidence to take advantage of it. Any attitude difference above that level of income is mostly accounted for by individual personality and intelligence. Someone however who was born to a working class family and grew up surrounded by people in blue collar jobs might not have the confidence or social network to climb as high. Or at least the path is noticeably steeper.

And on a personal note, I disagree with the comment "He has the right air about him, and the same freedom from anxiety and free-flowing creative energy of a college student because, for him, college (i.e. the time of life in which most middle-class peoples’ lives peak) never ended." At university things were just starting to get really fun. I'm mid thirties now and looking forward to the fun that's around the corner. Not only is the glass half full, but it's champagne and the cute waitress is coming round with refills.