Well, it depends on what kind of risk you’re talking about. I was writing mainly about market risk and volatility. Buffett is speaking to a different kind of risk, one that most investors don’t give enough consideration, and that is the risk of inflation.
Should inflation increase over the next few years a buyer of long-term bonds today would get creamed. Over the short-term the value of her bonds would drop dramatically (bond prices move inversely to interest rates). Still, if she held them to maturity she would recoup her initial investment but the money would be far less valuable due to the ravages of inflation.
By buying shorter duration bonds or employing a dollar cost averaging program an investor could avoid an outcome so dire. Buffett, however, would prefer to own high-quality businesses that have the pricing power to keep pace with inflation. In terms of inflation risk, he would argue that this is even more conservative than owning any sort of fixed income.
His point is valid and something all investors should consider. Balancing your aversion to volatility while limiting inflation risk may be the biggest challenge facing individual investors today.