The article makes the point that bonds don't even achieve this. At best, they decay in value less fast than cash in an inflation scenario. But because of yield rate fluctuations, they're significantly less liquid than cash (if you don't want to lose extra on top of inflation losses). Which is an issue because if the inflation rate is suddenly 7%, you can take your cash and put it in something much safer like real estate or foreign currencies. Holding long-term bonds mitigates inflation, but also makes weds you to it.