What arguments can't you credit?
Untrained or trained poorly or using aversive methods, mishoused, mishandled, needs not met etc etc, dogs will indeed pose a higher risk, add larger height and weight, heavier build and you increase that risk.
I don't think anyone has said otherwise?
Dogs with a good genetic background, well trained, well managed, needs met etc etc are far less of a risk, because they ARE very predictable, in fact actually the untrained, etc etc dogs are very predictable, the problem is that those owning them and putting people including themselves at risk, are not in possession of sufficient knowledge TO predict what will occur.
Of the recent cases to hit the media, I could have told you any one of them was a massive risk and what the flash points would be and what sort of attack might happen and when.
But no one is listening to the likes of me, no ones listening to the likes of experienced veterinary behaviourists with decades more work under their belts than I, who have been shouting from the rafters. No ones listening to the likes of ex cop turned forensic dog behaviour bite analyst Jim Crosby, who investigates dog related deaths and attacks in the US and has some interesting findings, including multiple cases where supposed dog attacks are in fact fabricated by people trying to hide child abuse and neglect!
One reason for that touches on your other point here - no ones campaigning to save these dogs, no ones saying dogs that kill should be rescued and rehabbed and sent back out to live with other people!
We do say it would be better, where possible, for dogs to be seized, taken to a secure facility where they can be assessed by behaviour experts. But we have very few such experts, or such facilities, so the dog ends up destroyed at the scene or soon after - destroying evidence (because at that point that is what the dog is), that could lead to better education, better bite/death prevention and better legislation to control human behaviour and action.
I fully agree, some people get dogs labelled as dangerous because they are labelled as dangerous - banning more breeds will not stop that! If it did.. we wouldn't be where we are now.