To make a long story short: Despite the data having been around for 40+ years the industry doesn't recognize the FC/CYA relationship and no matter what the CYA level never suggests more than 3-4 ppm FC. So algae was inevitable and algaecides had to step in to pick up the slack. Copper is a pretty good algaecide, it just comes with a whole host of side-effects such as staining, turning hair green, and it does nothing to sanitize a pool. Doesn't do anything but kills algae, but it is relatively cheap and companies jumped on it. So the copper bars were put there to introduce copper in to the water.
A properly managed TFPC pool has enough chlorine to destroy algae already, so there is no need for a supplemental algaecide and even in the rare situation that one is prudent, copper is at the bottom of the list of potential additions.
