I understand your suggestions, but although the original bumber might look very similar to the GEAR4's one, there is a major difference in the way they "grab" the device. While the APPLE's case feel loose on the metal antenna, the GEAR4's one is much more tight. As a matter of fact, i 've read in the MacRumors reports stating:
"How are you guys taking the band of? Seems to be a struggle for me, and I end up having pull the band from the sides with my nail. That leaves a mark that just won't go. It seems over time, there will be nail marks all over it
"
That is a problem on one hand, but on the other one seems to be keeping the steel of the iPhone 4 secure from dust, or other dirts that could get between the case and the phone.
And in any case, why should someone take care of a product that you paid to take care of another product of yours?! And even in that case, shouldn't that be stated on the package of the product, so to have in mind before you buy it?