You would need to have a yield significantly above the inflation rate for them to be a good investment. They made be a good hedge against inflation, but probably not a good investment.
The 8% inflation rate is a relatively short-term stat: 12 months. Even the rate of change today, is declining, at least partly because of resets -- ie., the initial jump in oil from 50 to 110 is huge, but now the 114 price will start to be compared to say 80 or 100, so the rate of change will show decline But TIPS, depending on what instrument, is 5 - 30 years. Apparently few think the current 8% inflation rate will maintain for those periods.
TIP is in relation to where-else you can put your money in bonds. The way to look at it is TIP/IEF. IEF is a substitute, based on duration. For me, it shows inflation is alive and well. People are buying TIP at a faster clip than IEF. Looking at just TIP and opining on its price is solving a 2 variable equation with one variable. Price is relative to its substitute. pro tip - for HYG, use IEI as the duration substitute.
%% LOL\right + limited that negative real return to 10K gross bond buy , much much less net. However to be fair, its more than most CDs; + WSJ noted even a finance planner that tried to help a client by some\got kicked off the website 2 times. So every little hint helps