Why aren't such breeds banned?
Well in 1990/1, the government wanted to look like it was 'doing something' in response to a number of high profile attacks by dogs on children.
At that point, pitbull type terriers were very popular, although the breed that triggered it all was in fact a Rottie, pitbulls had also been in the press.
The Kennel Club, the breed clubs all went to town protecting their breeds, because they're all registered breeds...
Except pitbull terriers, which are not. Funnily enough, nor are the other three breeds banned at the time, nor were there any examples of those three breeds in the country.
So four breeds were banned, one which was hugely popular but had no official representation and 3 that didn't exist here.
Hey presto, governments done something, all the little children will be safe, everyone will live happily ever after.
Only they didn't - because this didn't address WHY people were keeping bull & terrier type dogs that were a risk around small people and strangers, it didn't look at WHY these compact, economical to keep, robust, easy to train animals were popular with a disenfranchised youth in deprived areas, with drug dealers who wanted protection where having a dog is legal and a knife is not.. and so on..
It also didn't factor in that labelling these breeds dangerous, devil dogs, illegal... gave them a desirability they'd really not previously had!
And it really didn't help that you can create an illegal 'type' dog out of two perfectly legal breeds, or that a litter of puppies could contain legal and illegal animals, with no way of telling til around 9 months old.
So the numbers didn't go down. They went up. As did the numbers of people wanting them.
If you're asking why do people want them - loads of reasons!
Most of the bull breeds I have worked with are eager to please, exuberantly friendly, easy to train, easy to feed and keep, typically very healthy animals that rarely need the vets, whelp easily etc etc.
They have a stupidly high pain threshold and no understanding of anyone's (dog or human) personal space, they're still playing when everyone else is in pain and begging for mercy... so when they ARE eventually hurt - it has to be pretty bad. This tends to mean that trainers using aversives like prong collars, shock collars, yanking and kicking etc need to go very far to get a response...
In combination with that they're also remarkably fast learners AND sensitive little flowers mentally - they don't forget, and being terrier types under the bull breed macho appearance, the answer is 'get in there first, don't ask questions, just muller it'.
Another HUGE HUGE factor is the number of people who persist in teaching dogs NOT to growl - a growl is a warning, its a communication, it says 'give me more space/stop doing this' - but SO many dogs are taught via punishment NOT to give that warning..
When you combine all these elements, it is easy to end up with a dog who can do a lot of damage when they finally say 'fuck this' and are pushed over the edge.
Banning is not the answer though - we've done that since 1991 - it has not worked, by any metric you care to measure, it hasn't worked. Surely adding more breeds to a list, to try to improve on something that does not work... will also NOT WORK.
It isn't as simple as saying 'its not about the breed' because it is.. AND.. it isn't.
If we got rid of every bull breed in existance, someone would produce labradors with higher and higher pain thresholds (they're already half way there!) and a ready willingness to use aggression and bite (again.. ive met some seriously dangerous labradors as a result of horrific breeding and training).
Some people have a desire to own a dog that intimidates others.
Some people have a desire to own a dog that can do and is trained to do physical damage (look at the rise in popularity of bite sports, look at the number of celebs who have bought pre-trained protection dogs they're not remotely capable of handling or working safely).
Some of us just love the fatheaded lummoxes they are if raised properly - I won't live with em, they're too exuberant for me as I really can't be knocked around and trampled, but I bloody love training with them, they're hilarious fun, super fast to learn, do so with humour and a joy at simply working with a human.