Google webmaster tools does not claim to tell people what value is being given to the external links, it only claims to show what its bots are seeing. It is useful as such for people who want that info.

Oh and by the way, the secret KFC recipe is in fact just plain old salt , pepper & msg batter, but it is cooked in a special pressurised deep frier which is why it is so hard to recreate. It is the method not the ingredients that give it the edge.