The only thing that would worry me about a mandatory muzzling is that my dogs then don't have their best defence against the dogs of owners who won't follow the rules and won't muzzle theirs and thus those dogs that are the main problem now, will continue to be the problem.
If it were made mandatory and policed effectively, it might work for dogs in public that are attacking, but won't solve those attacks where dogs escape and then attack.
I think we need to go to source and clamp right down on breeders, so breeding dogs and selling them is heavily regulated, passing them on and selling them also heavily regulated - so the dog can always be traced, owning also heavily regulated and licensed, and large fines, prison sentences, loss of things that matter to people like this need to happen so having any dog as a status symbol is unfeasible.
I currently have to have a licence to watch BBC TV but not to own a dog. I could go and buy a bull breed tomorrow with no one caring and turn it into a lethal weapon either on purpose or by poor management and there would be no one to stop me until it was too late, but risk a £1000 fine for watching the TV without a licence. It's madness.
Unfortunately we don't even have enough police to enforce laws against humans, never mind control dogs so I do think that any controls that come in will be paying lip service, not cost much and be basically, useless.
I don't like stereotypes because I could be seen as this 'type' of person - single mum, low earner, housing association house - I tick a few of the 'scum' boxes, but unfortunately there is a certain type of person who seeks these dogs for looking hard, protection against rival gangs and the control (ha!) ego boost that having a dog like this can bring. They're not just a problem where dogs are concerned, they're a rising problem right through society and that's what needs sorting.