[user104658]

Honestly IMO it's a bit of both. There ARE gentler breeds by nature. Yes it's always the owner's fault but I suppose it's a bit like gun laws - guns don't shoot people themselves, but strict rules on gun ownership stops these things happening with anything like the same frequency.

There's no reason anyone "needs" a particular dog breed. There would be less serious attacks if people were limited to gentle breeds and smaller/weaker breeds. Maybe make it that you need training and back to a licence to own larger more powerful dogs.

This happens too often, and usually because inexperienced (or lazy) people have dogs that are beyond them. And they trust them too much.