And honestly, based on just that quote, I'd argue that John Shoven sounds like one of the most retarded or ill-informed Economics professors I've heard of. If one saves 10% of a super-mediocre $50,000 income for 30 years (never, ever getting a raise) and obtains a 5% real rate of return, they will have amassed $332,194 and can withdraw $21,609 annually for the next 30 years. That alone should be adequate for anyone accustomed to living off a $45,000 pre-tax income, in their old age. Also, after 30 years in the workforce they will be eligible to withdraw significant Social Security earnings, probably raising their total annual income to somewhere around $35,000+. That is, they'd be right on par with their previous 30-year earnings.
So, John Shoven, you are wrong.