I wonder if one if the prime drivers for entrepreneurship is bad management. I have to think that bad management pushes a lot of capable people out of their day jobs, and those people go on to become entrepreneurs.
Imagine a world where managers always recognized and rewarded their most capable people. It would be hard for a rational employee to leave a great job for a ten percent chance of creating something even greater. But leaving a boss who is Satan's learning-challenged little brother is relatively easy. And if the general economy isn't serving up wonderful job opportunities at other companies (thanks in part to bad management) then you can see why people gravitate toward starting their own companies.
You can thank The Dilbert Principle for some of this entrepreneurial zest. The Dilbert Principle observes that in the modern economy, the least capable people are promoted to management because companies need their smartest people to do the useful work. It's hard to design software, but relatively easy to run staff meetings. This creates a situation where you have more geniuses reporting to morons than at any time in history. In that sort of environment you'd expect the geniuses to be looking for a way out, even if Plan B has a low chance of success.
I've never seen a statistic on the number of companies that were started while an employee "borrowed" resources, from his day job, mostly in the form of time and Internet access, but I'll bet it's a big number.
Big companies with bad managers are the ideal breeding ground for entrepreneurs. Employees are exposed to a wide variety of business disciplines, and can avail themselves of excellent company-paid training and outside education. When you add broad skill development to the inevitability of eventually getting a moron for a boss, thanks to frequent internal reorganizations, it's no wonder that big companies spray entrepreneurs into the environment like the fountains at Bellagio.