The problem is that one has to be careful to distinguish between “Pit Bulls” and the breed that was originally associated with that name, the Staffordshire/English Staffordshire Bull Terrier. When I was a youngster ( not that long ago ) those two terms were synonymous. No longer. Pit Bull now is more properly used for those genetic abominations that derive from the Staffordshire Bull Terrier, but have been admixed with Bullmastiff, Doberman, and any of 50 other breeds purely for fighting and aggression.
Staffordshire’s are potentially dangerous and very tough ( as are many other breeds ). In fact they’re one of the few breeds that has been shown to be able to occasionally tough out distemper and win. Like all powerful dogs they can be a threat if improperly socialized/trained. They are a very dominant, territorial breed and therefore can be a handful. Amateurs should never own one. And they were bred for fighting originally. However…Traditionally the “well-bred” Staffordshire’s don’t have a reputation as people biters. Cat killers, yes. Dog fighters, to be sure. But it used to be when you walked down the “murderer’s row” of dangerous animals in a local pound you found two types of animals. Hysterically barking, flinchy, “shy-sharp” dogs alternately cowering and hurling themselves at you ( at most pounds dominated by ill-socialized German Shepard’s and Doberman’s ). And sweet, quiet dogs that come up and lick your fingers. These are the ones that are in for treating the neighbor’s cat like a bunny. And they tended most commonly to be Bull Terrier’s ( including the piggish looking English Bull Terrier which are notorious for getting into dogfights ).
Now you get HUGE ( well-bred Staffordshire’s rarely top the scale at 70 lbs ), slavering, snapping, aggressive ( and not the fearful, “shy-sharp” type either ) monsters - Bull Terrier mixes ( and the occasional Rottweiler ). Animals raised either explicitly for the underground fighting trade ( which seems to have exploded in popularity in the last couple of decades ) or just macho nuts looking for the biggest, toughest critter they can produce. These animals are often ( not always ) so fucked up genetically that they NEED to be destroyed, post-haste. No rehabilitation is possible.
A co-worker found an abandoned puppy near our job in a poor, semi-industrial, semi-rural district ( hard to describe area, really ). 6 or 7 weeks old. She tried to keep it. This poor animal greeted everyone ( quite happily ) with constantly snapping jaws. It was “playing” - But not like any puppy you have ever seen. It would have quite literally been a threat to it’s littermates. At 8 weeks it had jaws like a vice and could not be controlled by my very experienced co-worker. Five, FIVE, separate vets had the same advice - It needed to be euthanized for it’s own good. It was a walking time bomb.
Well-bred animals are not like that. They can all be trained, socialized, and turned into “good citizens”. Even the hard breeds like the Bull Terrier’s. And the aggression can be bred out of them ( as has been done with great success with the English Bulldog ).
I don’t think banning whole breeds is necessarily the best solution ( but I agree it is a debatable point )in all cases. Often they have traits, other than their aggression, that make them desirable. Bull Terrier’s really can be incomparably sweet animals . Better to breed ( and train ) out the aggression ( or the worst of it - These are carnivores and you’re not going to get it all ). And crack down heavily on the backyard puppy-mills and dog rings that produce the monsters.
Just as an aside, the Canary Island Mastiffs that killed that poor woman are extremely dangerous and their breeding was at one time banned by Spain because of it. In that case I think you can make a better case for banning that whole breed. I’ve never heard them described as anything but nasty, even by Mastiff breeders. And there are certainly other breeds that do fall into this greyer area for me.
But I do like the “original” Pit Bulls .
Disclaimer: I have not now, nor have I ever owned a Bull Terrier - Just known many. I’ve had an Airedale Terrier and a Chesapeake Bay retriever. Currently I just have a cat .