It all boild down to "Prior Art".
Which is all fine and good, but the patent office only thinks that "prior art" is that which is patented. Something outside that has been know for eons, just doesn't fit the bill.
In some cases, fortunately, we get judges, and (hopefully) juries that understand "common sense".
So, the patent office will patent, and the courts will continue to rule invalid. Life goes on.