I bet EVERY person who calls Apple Returns is offered a FREE bumper. If they don't they're gonna lose a lot of business. Its such an inexpensive item, they'll quickly eat the cost to placate their customers.
They SHOULD give out free bumpers, though. They cost like 5 cents to make and they're selling them for $30!!!!!!
Personally, I believe that Apple was well aware of this limitation and made bumpers for this particular purpose. It's funny how in the past 3rd parties used to supply these accessories, and now Apple is in the business. Most likely, they foresaw this need due to the attenuation experienced with a weak signal. The traditional designs usually covered the entire back. Its odd how these are designed to hug the antenna.