Sure, you can burn down your principle based on life expectancy. But that's only really useful if your old. At 40 even 1% in your first year will probably cause you to run out of money.
source: http://www.investopedia.com/ask/answers/042415/what-average-...
Basically, you take out a lower percentage of your money on good years than bad. Further, you need to take taxes out to cover inflation. Aka, you pay taxes on 7% even if your real return was only 4%.
PS: There is a reason many institutions are ok with a very steady 3.5% ROI there is a lot of risk going for more.
[1] imo it's okay to do this while you're in the workforce since you're salary effectively acts as your fixed income portion of the portfolio.
http://blog.cordantwealth.com/how-much-can-i-spend-in-retire...?
Considering there are 1,810+ billionaires globally you have not heard of most of these people. But, if someone is defined as unusually rich not just 'comfortable' that seems to be the new movie millionaire.
In many ways the gap between 30k / year and 300k/year is larger than the gap between 300k / year and 3 million per year.
PS: I actually know several people that inhered low to mid 7 figures. But, they are really more upper middle class than the kind of 'Rich' you see in a Hollywood film. But, plenty of people would consider that rich.