A comment by Lewk in one of the "unionz R teh 3vil!!1!" threads got me to thinking.
This comment is actually not true. FAR more "responsible" for success are luck and brains (indirectly luck, because that's mostly determined genetically).
But the "bootstrapping" Horatio Alger myth is very popular in America. Why? I suspect it is the confusion of "necessary" with "sufficient." Scientists love these terms, because they make a critical distinction. For example, activity of gene X is necessary for cancerous transformation. You don't get cancer forming if this gene's activity is missing. But is it sufficient to drive cancerous transformation? These are functionally very distinct ideas, but they are often conflated by sloppy thinkers.
For example, work ethic is very nearly necessary for economic success. Very few people achieve much in the absence of hard work. But here is the key: hard work guarantees you virtually nothing but an actual job (and in some economies, ahem, even that won't suffice because nobody wants the hard work with your particular skills in your locale). You need a large amount of luck for that hard work to be applied such that you can be very successful. First, there is what you are born with. If you have a below average IQ, it will be very difficult for you to be professionally exceptional in any way (the exception being the "entertainment" industry, which is an economic freak anyway). Second, where do you live? Third, what skills could you acquire as a child? What role models did you have? What opportunities did you have?
If all of those things break fairly well for you, then you are in a position to maybe be able to work your ass off to be very successful. But there will still be a lot of luck involved. For a very successful person to say "I am here purely because of hard work" is the height of arrogance. The hard work was necessary, but it certainly was not sufficient. Even people who came from hardscrabble roots had strings of lucky breaks to become successful. Look at Ray Charles: blind and dirt poor. But if you look at his career, he had a lot of lucky breaks. In other words, there were a lot of potential Ray Charles out there who worked just as hard but weren't in the right place at the right time. Is there skill in positioning yourself optimally? Absolutely! But there's even more luck.
The best thing that can happen to you is to be lucky. You hear this in science and sports all the time: "I'd rather be lucky than smart/good." This is certainly the case with most Nobel laureates. When you look at their careers, there are almost always many exceptional scientists who were just as god but never got any lucky finds. There are, of course, genius exceptions like Barbara McClintock. But really the most important thing is lucky, and truly the best road to wealth is tpo be born with it.
Look at Bill Gates. Smart, exceptionally hard working. BUT, he was born into some wealth, went to an elite private school, and by pure luck had truly unusual access to embryonic computer technology: in the right place, the right time, the right inclinations and native skills, and with exceptional resources. THEN is when the hard work kicks in. This doesn't belittle Bill Gates. Lack of hard work would have sunk him. But his hard work was not sufficient to get him where he is. The same kid with the same work ethic in the same city at the same time, but born to a different family would not have become Bill Gates. COULD not have become Bill Gates. Luck was also necessary. Luck at several levels.
The reason I hate this Horatio Alger myth that hard work is sufficient is that it is deeply insulting to everybody who works like a dog and isn't successful. It almost goes so far as to say that there is something lacking in somebody who isn't successful. And that is deeply offensive to many of the working poor. I so often read about people who work 2 or 3 jobs to feed their families. Since they came from nothing, they make a pittance. But their are neither slothful nor stupid. In fact, I talk to the custodians in my building at work, and I find that many of them are immigrants who work like dogs. One mother of two is from Costa Rica and works 8 hours/day as a custodian (4 pm - 1 am + 1 hour for "lunch") then cooks/waitresses lunch shift at a local tacqueria every day and weekends. She's not successful.
I think a large part of why the Horatio Alger myth is so popular in the US is because history is written by the victors. Or, in this case, by the wealthy. If you have the money and soapbox to get your interpretation out there, that is the interpretation that will endure. Everybody interviews oligarch X to ask him how he became successful. nobody interviews the mother of 2 from Costa Rica who works 70 hours/week. And frankly, nobody cares to hear her story.