When Apple was testing these devices out in the wild they had to use cases to hide them. Proof was in the one found at the bar. Guess I will go stand in line at 7am just to get a bumper lol.
While testing, they notice iP4 signal problems without cases.
"Oh, why don't we introduce some "bumpers" that fix the problem and charge them an extra $30 for it.
Once people realize that the bumpers solve the problem, they'll fly off the shelves."