I agree with what your trying to say to a point however I don’t know how the line would be drawn.
I mean labradors and golden retrievers are large and powerful. Newfoundland’s and other giants are typically slow, calm, gentle and often used as service or rescue animals.
Then you have the likes of wolfhounds, greyhounds and the like which are typically calm and gentle. So large does not necessarily mean nasty.
What I would agree with is looking at the breeds that pop up time and time again repeating the same behaviour and look at the reasons why. It’s almost always a repeat of the same pattern…bull breed type, newly acquired or unknown history, more often than not uncastrated male, history of aggression previously, no formal training completed, not enough stimulation or exercise, no background on dam and sire genetics or temperament, owned by dare I say a certain type of person. Maybe that’s the sort of thing that should be focused on rather than the size of the animal.
The vast majority of people with larger dogs are sensible. I for one spend so much time training, socialising and exercising my dogs mentally and physically. I am very strict with the rules around my dogs and children (or adults for that matter!) because a dogs a dog but I don’t think it’s fair to say because mine are large I am an irresponsible person. There are so many more factors at play than that.
I do 100% agree that owners should be prosecuted for irresponsible dog ownership though!!