I would instead argue that when people think of backing as a problem what they are really concerned with is guaranteed liquidity. Unfortunately, even if we made it so you could always buy names with bitcoin (perhaps with an automatic variable exchange rate to avoid the backing problems I suggested above) it wouldn't really solve the liquidity problem because you might want something _other_ than names, like food. And if you were having problems getting people to accept bitcoin for food then you're going to have pretty much the same problem with bitcoin-connected names for food.
Just to be clear, Namecoin has the features of bitcoin (since it is a fork of bitcoin) plus the distributed data store, you wouldn't back bitcoin with namecoins, you would use namecoins instead of bitcoins.
It wouldn't completely solve the liquidity problem but it would help, if you want something other than names, like food, and if you were having problems getting people to accept namecoin for food, you could sell it to someone who does want the naming feature and buy food with the proceeds.