What happens unfortunately is "what sells". People are preoccupied with parental titles, and want a puppy who "has it in him" to become the next great champion. So the same lines and combinations are bred over and over, eventually minimizing the gene pool and crossing more of the same, which produces diseases and defects. Similar to human close relationship marriages, children can be suffering from dwarfism, rare genetic diseases, Down Syndrome, etc...Very sad, as consideration in breeding must be primarily on quality and health of the breed, championship titles are hard work, it is not just "in the blood". Very foolish to assume that if both parents are titled champs, pup will be the same naturally. As with every child, parents develop potential of the child and the fact that 2 parents are Noble Prize winners, does not guarantee the child will be a rocket scientist.