As someone else who has worked with dogs for many many years, I wholeheartedly disagree with this. It's the hill that I will choose to die on.
Breed and genetics play a HUGE part. You cannot train genetics out of a dog. There are many breeds that should NEVER have been domestic pets. You can reduce the risk to an extent by being a responsible owner who understands and meets your dogs needs 100%, but a large number of dogs aren't actually in the right homes or with the right owners. Fortunately for the vast majority of people this doesn't lead to catastrophic outcomes, but in the tragic cases that reach the news, it does. A miniature poodle who is lacking the mental stimulation that they require, is never going to have the same dire consequences as an XL bully would in a similarly unsuitable environment.
Puppies aren't born bad, however, they are born with a genetic predisposition to certain characteristics, to deny this and say that it's all down to the owner, is absurd. If it was all down to the owner and training, then why do we pick specific breeds to be police dogs, service dogs, herding dogs etc? It's because of genetics, hence why we don't just pick any dog for those tasks.
People repeatedly buy unsuitable breeds, that have significant power and genetics that don't lend themselves to being domestic pets, and then claim they are shocked when it all goes wrong.
I adore dogs. I spend my life with dogs, but we are doing them a disservice by repeatedly forcing them to fit a domestic mold, when some of them just don't. None of this is the dogs fault, it is all the fault of people who refuse to acknowledge the genetics and potential that their dog has.