Not all dogs are created equally.
One of the biggest issues with dogs is that most *known* breeders are breeding for conformation and not functionality, which goes hand in hand with health. Purebred does not mean well bred.
Most show line breeders breed for family pets as well so most of the dogs bred by these people can be found in your average home.
A working line German Shepherd looks nothing like a deformed show line German Shepherd.
My dobermans are working dogs and we are in a working dog Schutzhund club. Almost all of the dogs in the club are German Shepherds and almost all of their owner/handlers breed.
However, they only breed the best performing dogs that can endure trials and win working titles. These people are more concerned with how well a dog can preform and not on how it looks. The breedings are highly researched well in advanced to see which pairings can yield the best performing pups. These are perfect examples of selective breeding for the betterment of the breed.
Like in natural selection, only the strong and most fit get to pass on their genes to the next generation.
So, these dogs are still purebred as well as *well bred*.
These dogs are bred for specific working traits: ability to physically work in the field and through obstacles, high drive, high nerve, and heart. Qualities many pet/show dogs do not posses.
And since working dog breeders only breed more working dogs, most people who only want pets do not go to these breeders for their pups. Nor are many of these dogs suited for a easy going family home. Their drives are just too high.
So, folks that are just looking for a family pet go to a 'reputable show breeder' instead and just continue promoting the breeding of 'crappy' dogs. I know the AKC specifically is destroying a lot of breeds and their original function/purpose. Many AKC dogs look very different than their original counterparts 100 years ago. And those dogs 100 years ago were bred for a specific purpose or work. For function.
I have an 'original style' purebred miniature pinscher. She's 20 lbs and a tall lean machine. She's several times larger than an AKC min pin(seen below). However, she is what the breed looked like originally. Her drives are high and she wants to hunt. The breed was originally designed for eradicating rodents & pests and she's very good at it.
Today, the average min pins are 8lb fat lap dogs.
https://scontent-a-pao.xx.fbcdn.net/...710_7720_n.jpg