Are Americans Becoming Too Risk-Averse?

Come join us for an informal philosophical discussion. No prior knowledge or research is required, but an open mind is.
For much of its history, America has celebrated the person willing to leave home, change careers, start a business, or otherwise gamble a comfortable present on an uncertain future. But are Americans becoming less willing to do that?
Nowadays Americans move between states much less often than they once did, and the rate of new-business formation remains considerably below its late-20th-century level. Economist Tyler Cowen has argued that Americans are becoming increasingly complacent - "setting our sights far too low" - and losing some of the country's traditional appetite for change and experimentation. Of course, avoiding risk can be perfectly sensible. Someone supporting seven children, for example, may have excellent reasons not to gamble with their livelihood. But what about someone prosperous enough that failure would only be embarrassing rather than ruinous? Suppose a comfortable office worker dreams of starting a company, becoming an artist, moving overseas, or simply doing something unpredictable - but spends forty years choosing security instead. Is that prudence, or is something valuable being lost?
Further discussion questions:

• Could a society become so good at providing comfortable, predictable lives that it accidentally produces too few adventurers?
• If you can afford to fail, is there something regrettable about arranging your entire life so that you never do?
• Where is the line between courage and mere recklessness?
• Does a society need a certain number of unusually risk-tolerant people even if most individuals are perfectly rational in choosing security?
• Would you rather reach old age regretting a major gamble that failed, or regretting a major risk you never took?