Also, about your little case study -- 1000 people constitutes a large enough swath of 300+ million Americans, so I don't have a problem with 5 people that actually exist being a good enough case study.
A guess as to your observation: Do you know what kinds of jobs they've had as teens/young adults? Many of the starter jobs are related to sales, in some form or another (best buy, verizon, places teens know something tech related might work, even places like carwashes, etc), and (just spitballin here), I think the role of a silver tongued deal-maker is very popular in many upper to lower middle class and even lower class groups. Marketing seems like a natural extension of that. Also, I've always thought of marketing as the attractive, relatively business-minded person's liberal arts degree (but maybe that's just me).
Also, on self-esteem, it's sometimes something you can't tell from just looking. It's kind of their job as marketers to have very very high self esteem. If you get a pitch from a marketer, and they look like they have even the slightest doubt that their plan will fail and NOT bring in piles of cash, then you're dealing with a bad marketer.
Regarding their jobs, I'll just list them by their initals. A. Promoting, Organizer, Black Hat SEO for a while. B. Freelance Computer Repair, programs PHP. Wants to build a business once he's 18. D. Computer Sales "Afilliate" proably hits it closest. Then some other gigs he didn't (want to) tell me about. D. Drug Dealing, lower-mid distribution chain. He did it in highschool because it was easy money. J. Marketing in an ad-agency, and for some reason he quit biomed to become carpenter. J is an outlier.
I have to say though that only 3 of them are Americans.
On self esteem, I've spent considerable time with this group, and I'm relatively sure that they've got high self esteem, regardless of whether they were marketing or not. It's generally hard to judge a persons self esteem acurately. You can generally guess it after spending some time with the person, seeing such things as their general confidence (which is expressed through body language more than you might think), and how they react when encountering opportunities and obstacles.
"This works, but I see another way to look at it, witch removes something I don't like about the idea" Call it rebelling, call it out of the box thinking. It's what happens with us all, so we are not clones of our parents.
At least that's what I've seen in the small group of entrepreneurially minded kids I've met and got to know(4-5 people, a ballpark estimate would be 1% or less of people I know).
I also don't entirely agree on the financial backing part. 3 of them have financial backing, but all 3 earn their money themselves. The other 2 have no, or almost no financial backing. One of those is an outlier, since he had backing from his father, but it's uncertain whether he'll have it in the future.
One curious observation that I've made is that they all have a slant towards doing marketing. 2 of them went to college in order to study it, another 2 are doing freelance work at it, and the last one is intrested in it.
Also, 4 of them program, the 5th one not being intrested in it.
On the point of self esteem, they all seem to have very high self esteem.
I have to say that 5 people is a small set, and whether they'll be sucessfull as entrepreneurs is only something time will tell, so I've only included characteristics that occur in most of them very strongly. Still, it's a set of teenagers/young adults that allready know they want to be entrepreneurs, so it fits quite well.