Training and keeping control of their dogs. Like any breed, pit bulls have needs in order to be happy and well-adjusted dogs. Relevant here is that, just like any strong dog with the possible exception of some of the gentle giants, they need extra discipline and a firmer touch in training.
A properly trained and socialised pit bull that's treated well will not attack people or other dogs, whereas untrained and/or not properly socialised dogs of ANY breed are likely to develop problem behaviour, which can include aggression.
Which job are the owners not up to doing?
Training and keeping control of their dogs. Like any breed, pit bulls have needs in order to be happy and well-adjusted dogs. Relevant here is that, just like any strong dog with the possible exception of some of the gentle giants, they need extra discipline and a firmer touch in training.
A properly trained and socialised pit bull that's treated well will not attack people or other dogs, whereas untrained and/or not properly socialised dogs of ANY breed are likely to develop problem behaviour, which can include aggression.
Why do pits need "extra discipline" but labradors don't?
This is a tautological argument, because every pit who attacks another animal or person will just be written off as "improperly trained".