Tbh, the whole "it's not the breed, it's the owner" shtick reminds me of what we frequently hear from the US regarding the gun control debate..."it's not guns that are the problem, it's gun-owners!"
Yes, there are some responsible owners of XL bullies, just as there are some responsible owners of guns. But the trouble is that there a lot of people who aren't responsible. As such, a ban makes perfect sense to keep innocent people safe. Particularly when owning such a thing isn't a necessity.
I'm sure there will be plenty of outspoken XL bully owners aggrieved by this decision, but they're not worth listening to.
Why on earth any normal, sensible person would want one of these god-awful things as a pet in the first place beats me. If you want a dog, just get a proper one - a Labrador or golden retriever or something. Why the would you want a bully XL?!