The problem is not with the examiners, but with the law that governs that examination. That law makes it possible to get patents on ideas that any ordinary person would find old, well-known, and obvious.

via How Amazon got a patent on white-background photography | Ars Technica.

The result in Hear-Wear explains the result in the Studio Arrangement patent application. In both cases, the inventive idea, embodied in the independent claim, was shown to be old and well-known by a prior art reference. And in both cases, a seemingly trivial add-on feature in a dependent claim ended up being the feature that tipped the balance from obvious to nonobvious—a multi-pronged plug in one, and a distance ratio in the other. Because in both cases, that trivial feature was so ordinary that no one would have taken the time to describe it in a printed publication, but without such a publication, according to the Federal Circuit’s rules, obviousness cannot be proved.

This, in my view, is why the examiner did not even attempt to reject claim 3. A distance ratio may seem trivial, unimportant, or uninventive, but absent a written prior art reference, that distance ratio can sustain a whole patent claim. However obvious such an element may sound, it remains nonobvious according to the letter of the law, and that is all that is needed for the patent application to leave the examiner’s desk and move to allowance.