I would argue that most of those are bad patents, which should not have been issued. One of the criteria for being awarded a patent is that your invention be non-obvious to an expert in the relevant field. If just looking at the product is sufficient to disclose everything you need to reproduce it, that doesn't necessarily mean that the idea is "obvious", but it should give one pause, and warrant further investigation into whether or not this particular invention is really worth patenting.

No, my comment applies equally to "good" patents. When someone invents something truly non-obvious, it is still usually easy to figure out by looking at the results, so the "revelations" in the patent application are of no value. As a society, we have no interest in giving people a monopoly over truly non-obvious inventions unless failing to do so would make the invention not happen (which is a different argument than the revelation one).