Agreed. We can't keep everybody, and if there is anything the Packers seem to be good at these days it's developing the OL.
King has the skills. What he lost is his speed. What every athlete has to figure out is how to stay competitive as age increases and speed decreases. King has not recognized his decrease in speed and agility, and therefore is getting burned. IMO, cornerbacks are better able to use angles to their advantage covering on the inside, which can mask a lack of speed. On the edge it's all about the hips, change of direction, and flat-out speed. He's no Darrell Green, so he'd better figure out how to be the crafty DB or he'll be out of a job before he knows it.