Gold and USD is even easier to steal because it's damn too expensive or impossible to protect them. You never actually own USD, by the way, it's always in some banker's balance sheet. See also: http://en.wikipedia.org/wiki/Executive_Order_6102

Protecting Bitcoin by splitting the password via 7-of-12 SSSS and sending the keys to 12 of your friends around the globe costs almost zero. The amount of security does not depend on how much you are willing to spend on it. It only depends on your paranoia. Most of the people are safe enough with cheap offline computer. Fugitives can use more complex schemes.