Throughout all of time, there have been people who have kept dogs badly and/or cruelly - throughout the UK, there are many other breeds kept like this too. Those other breeds are not killing people regularly though, are they, including grown men?
It is just beyond belief that anyone still thinks these are 'just a dog'. They are way beyond that. Thankfully I see very few of them round here, but when I do I just have a complete gut reaction to them to avoid. I have owned and loved dogs all my life and have lived with multiples of giant breeds.
One I do meet occasionally, and I was talking to the owner the other day and explained that sorry, I appreciate that ostensibly the dog is as good natured as you could wish - but I still have a total wish to avoid him. As I was walking away and pondering further, I think it must be that my brain recognises that he probably won't attack my dogs or me, but if he did there is probably not a damn thing anyone can do to stop him until my dogs are probably dead and people are injured.
I think the trouble is that their owners are convinced they have control, either through hard work and training, or through sheer idiocy and superiority complex. They are kidding themselves. It's not just the dog's weight, it's the body composition and muscle mass, and the low centre of gravity/stability.