Pitbulls can be a wonderful dog. All dogs can be. I think the proportion of negative data on pitbulls is due to a few factors, including
- Negative media reinforcement - lots of studies utilise news media as a primary source, and news media responds more frequently and aggresively to 'pitbull' popularism.
- The breed characteristics that make the breed good for fighting, guarding, killing, attract a high proportion of shitty owners. Nature Vs. nurture is therefore skewed.
- Dog attack rates for breeds actually pretty closely follow dog ownership rates. FATAL dog attack rates heavily leans towards dogs that have the capacity to inflict fatal wounds. So naturally this more heavily follows breeds such as pitbulls.
My dog is a pitbull cross and is a wonderful animal. It is 35kg's (77lb) and could easily kill a human. It did not have good breeding, unfortunately. I have had him from 8 weeks, and treat him with love and respect. He has taken what I have given him and reflected it back to me, magnified 10 fold. The only emotions he shows are love and respect to all humans and dogs.
He has attacked a dog once - a bull terrier we encountered out in the wild when walking my jack russell with the wife. This bull terrier (unprovoked) attacked and bit down on my jack russell. I grabbed the bull terrier and restrained it against the ground, so it let go of the jack russel and it tried to attack me.
My little man locked onto the terriers face and restrained it whilst I stood up, composed myself, then grabbed the aggressive bull terrier and threw it over the fence (it had got on the wrong side of its fence on a large farm). As soon as i was in control again, my pitty cross backed off straight away. He had the opportunity to savage this dog, but he just did what he had to do to protect me, and no more. A beautiful soul. Whereas i go on a walk with him and people often malign me for how he looks. Fear mongering, no more no less.
I am sure there are bad pit bulls out there, but outside of the rare care of careless inbreeding, I believe all of the breed reputation is from nurture, not nature. Even a basic search of wikipedia backs this stance up.
https://en.wikipedia.org/wiki/Pit_bull#Dog_attack_risk