And another thing, what's the risk in buying bonds that would give the unadjusted one a higher return?
Interest on a bond is a charge for the use of money which reflects also the projected purchasing power of the future interest and principal, the fact that such purchasing power is unpredictable, and the risk of default by the borrower. Given two bonds of identical maturity and issuer, one of which eliminates inflation risk (i.e. reduces the volatility of inflation adjusted returns) and one of which does not, the latter will be priced to yield more.
The above, unlike the rest of our dialogue, is objectively the way things are. If you don't believe me, please ask a knowledgeable friend about it. Or just give it a little thought yourself:
TIPS offers inflation +3% and you expect inflation to average 2%. But even if you are right, it will sometimes be 0% and sometimes 4%. Therefore, if priced at 5%, your average inflation adjusted return is, indeed 3%, but your actual return will sometimes be 1% and sometimes 5% and if you've mis-estimated inflation it can go either higher or lower. Fundamental theory of investment, as well as logic, results in a premium price paid for the bond with lower (after inflation) risk. Therefore, people pay more for it, thus reducing its yield.