OG - while I understand what you are saying, I must respectfully disagree.
First off - unless the breeder has the histories of every single puppy that was a product of their kennel (this would include all offspring of any puppies that they sold) then they CAN NOT be certain that their lines of free of genetic defect.
Also - in this day and age of the internet, I wouldn't take the word of a website as to the perfection of someone's breeding lines. Since many people shop for a dog on the world wide web - having a breeder put on their website that their dogs are free of disease but having nothing to back up that claim would be a MAJOR red flag for me.
Someone who is truly an ethical breeder - breeding only for the betterment of the breed and not the money in their bank account - would not balk at getting OFA's and Cerf's done on any dogs that they plan to breed.