There's a lot of problematic logic flying around here.  If the bond market is perfectly efficient, there's not really much point to discussing bond investing choices.  Use the dartboard to buy individual bonds and never pay a penny above minimum expenses.  Likewise for the stock market, since there's no reason to think that projections of earnings growth are more or less reliable than projections of default rates or interest rate movements.  Of course most of us think that the market is less than fully efficient, especially for a relatively new product like TIPS that is linked to a variable, event-driven, government-controlled index.  

Furthermore, if inflation is predictable, it wouldn't really make much sense to buy a hedge against it (which is really what tips are - anything adjusted according to a non-fundamental metric like inflation is a hedge rather than a real return investment play).  Hedging is for unpredictable events, like earthquakes.  In a lot of possible futures, TIPS would yield the same as less than regular bonds.  However, in the future where we're getting ravaged by inflation, assuming the government doesn't mess with the CPI further, TIPS would outyield regular bonds by enough to balance how much we're getting losing in real return on other fixed-income products and cost-of-living.