Because most people don’t understand the scale of what a billion dollars really is.
There were 920,000 new millionaires created in 2014 alone. A study by Credit Suisse claims the world’s millionaire population is roughly 35 million and is expected to reach 53 million by 2019. Becoming a millionaire isn’t easy, but nearly a million people manage to become new millionaires every year.
In contrast, the global billionaire population is around 2,000, a small fraction of the estimated 35 million millionaires. And that is because a billion dollars is 1,000 times larger than a million dollars. You are talking about being a millionaire 1,000 times over.
In order to earn that much money (legitimately) in a lifetime you have to build something really big and extraordinary – something that is needed by millions and millions of people. 8 of the 10 youngest billionaires in the world are in technology (Facebook, AirBnb) and created products that are ubiquitous. The larger list of billionaires includes innovators (Bill Gates, Steve Jobs, Elon Musk, Jeff Bezos) as well as industry moguls (Walton family, Koch brothers) and investors (Warren Buffet). Their influence touches millions of lives each day.
Not many people can even conceive of an idea that would impact the lives of millions of people, let alone act on it and execute that idea. In most cases, you literally have to change the world: create new industries, new products, or overturn old industries. None of that is easy: In fact, twice as many people have climbed Mount Everest (4,042) than have become billionaires. That should give you a sense of the sheer scale of that challenge, and unlike Everest, there is no Sherpa who is going to push/pull/drag you up the mountain to help you get there.