This is as simple as I can say it.
Health testing is great and I never said, nor implied, not to do it.
But health testing is like trying to close the barn door after the horse is out. The goal should be to breed dogs in such a way that inherited diseases do not become common in our breeds.
The kennel club breeding system, from it's very starting point of the meaning of purebred which means all dogs in any breed must be, all related to each other usually from a very small founder population, no new genetics brought in, constant use of inbreeding (there is no choice even if you do not want to inbreed), closed stud books and popular sire (and you can link this to showing if you like) effect. All need major review and updating how we do things.
I think you've expressed the whole purebred situation in a nutshell with this statement, Shortstep. ( A very difficult thing to do, by the way!! :D )