Wow, this thread spiraled out of control pretty quickly. Pitbulls are used in fighting rings because their strong jaws in addition to their genetic sense of loyalty (wanting to please their owners) make them easy to train and "entertaining" to watch. Pitbulls were the original "nanny" dogs, look up some old pictures... you'd be amazed. My biggest problem with pitbulls is the people who (often) own them. Young men who want a "tough" looking dog, with no desire to train or knowledge of how to socialize it properly. Do I get nervous when I see a pittie approaching... sometimes, especially when I spot who's on the other end of that leash... but I've met some incredibly sweet pit bulls and my dog is friends with a few at our local dog park. Dogs from fighting lines, bred for generations to select for aggression, may be beyond hope. But that's not the vast majority of pits. Oh, and for all your evidence, go look up the list of dog bite prevalence by breed... you'll be shocked at what you see. (Spoiler, pit bulls are NOT the number one breed involved in dog bites in the US).
As for Goldens and the nature of retrieving dogs (now you've hit on my breed
) No, the bird is not always dead when it lands. But the dogs are bred for a "soft mouth" and should not take it upon themselves to finish the job. A glancer should arrive to the hunter's hand still alive, provided it doesn't bleed out before getting there.