I've had a Rottweiler from Battersea, years ago. She was the gentlest dog i have ever encountered. However, when I took her to my parents and she saw my dad for the first time, who was wearing a hat, she barked very ferociously, and I saw what she was capable of -very scary. My dad became the love of her life, btw, and I never ever saw any behaviour like that again from the dog. My sister had four small children and although they loved the dog, I NEVER let them be alone with it -not because I suspected anything but because a dog is a dog. It is an animal. It cannot be trusted absolutely.
However, several years later, after my dad had died and dog was too strong for my mum to walk (and I wasn't around for a few weeks) my mum found a dog walker. All very satisfactory. However, I came home one day and found the dog walker having a cup of tea in my mum's kitchen, with the dog under the table. The dog walker's three young children were crawling all over the dog, (and I understand the dog had gone there to escape the children) and the dog was growling at them! WTF! I pulled the children out and told the dog walker who just replied, 'Oh, X (the dog) is fine, she loves my kids.' Even if she wasn't worried about her children (and I certainly was) the dog was unhappy! I think she was really stupid. That's the only way I can explain it.
My views on dogs have changed since becoming a parent. My DS is terrified of dogs. He has been bitten on three occasions by small dogs. Two chihuahuas, one cockerpoo. (I was bitten by a dog and several horses (!) as a child and am not scared of any animal). The problem with these dogs appears to be that the owners carry them, maybe because they are so small, or maybe because they are fashion accessories. So the dog -who probably thinks it is a handbag- is eventually put on the floor, and is scared, and bites anything that goes by it. (This happened to DS, walking home from school with DH, minding his own business, and the dog leapt out of a door way (at the end of a pink sparkly lead), and bit him. Owner didn't even apologise.)
So now I think that having a dog is wonderful, the relationship a child can have with a dog is so special. But some dogs make better pets than others. Dogs which are close to the working strain make less good pets because they are closer to being dogs than being domesticated animals. And the bigger the dog's mouth the more (physical) harm it can do (bearing in mind a chihuahua traumatised my DS). Bull types have locking jaws with more cubic pound capacity then a poodle or spaniel or small mongrel. If you have a small home get a small dog. If you have a huge outside space in rural areas, then yes, get a big dog.
Surely it can't be much fun if you are a big dog, all cramped up in a small flat, then allowed limited outside time, probably in a park or walked on crowded streets, when genetically, and not that many generations ago, your ancestors were bringing down bulls or used to taunt lions or herd sheep.
And yes, I do blame the deed and not the breed. BUT that being said, unscrupulous breeders who don't care about the temperamental stability of the animal they are using are surely more at risk of breeding temperamentally unpredictable dogs? I am aware that this strand of thought appears to imply that only rich people can have dogs because only they can afford the high fees for a quality puppy -and even then, these might bite.
One repercussion of this dreadful incident is that adoption of rescue dogs may decrease. After this, could you trust a rehoming centre's assessment that a previously abused dog was safe around children?