Yes backyard dog breeders are bad and should be avoided.
Backyard dog breeders are not very knowledgeable and are considered amateur.
When dog breeders are not very knowledgeable in breeding dogs then there becomes problems of breeding dogs that should not be bred together which then creates puppies that are sickly, retarded etc.
Backyard dog breeders really need to be stopped because it's bad for the animals and bad for the animal population as well.
We have too many puppies and dogs in shelters that need homes yet people are buying from dog breeders and leaving those puppies behind.
The world has too many puppies and dogs and we need to actually quit breeding them.
However if you do buy a puppy from a backyard dog breeder then expect the dog to have health problems and other mental problems as well.