Coziness is the biggest hurdle. As a programmer, I can make a really good salary at a tech giant. Even after 4 years of grinding and finally achieving product market fit and growth, my wife doesn't understand why I'm doing a startup. Life could be so much easier working for Google.
Heck everyone has a job here. The 2/1,000 missing entrepreneurs don't have an incentive to start. I'm from Ottawa and all my friends work for the federal government with big fat pensions and doing boring work (my perspective mind you). But they have great family lives, lots of vacation and great outside of work experiences. Why the hell would they jump into entrepreneurship? Worst of all, the government workforce is growing faster than that of the private sector!
What worries me most is the future - a country cannot get wealthier nor innovate without entrepreneurs. It is s a real concern indeed.