The big risk would be in running out of money after xx years because you're barely keeping pace with inflation.
You'd be better off buying 100% tips. At least they'd protect you in the event of a surge in the CPI.
You'd still probably find yourself losing buying power after a decade or two.
Try target retirement income, lifestrategy income or wellesley. At least the stock component of those will give you enough long term appreciation to keep the buying power up.
Be fearful when others are greedy, and greedy when others are fearful. Just another form of "buy low, sell high" for those who have trouble with things. This rule is not universal. Do not buy a 1973 Pinto because everyone else is afraid of it.