I am inclined to believe dogs tend to be reflections of their owners, I have had a Dane Doberman cross, a Doberman and a Wolf hybrid, all of which became huge lap intelligent lap dogs
Pit bulls reputation suffer from 3 problems. The first is being breed to fight, that instinct is in them as much as my new black lab pup has the instinct to fetch a ball. Second is for some time the first was the reason a bunch of Richard Cranium types got pit bulls, every drug dealer, gang banger and wanna be bad guy had one and as dogs reflect their owners they created some monsters, which they let breed indiscriminately. But, the final problem is also reflected in a lot of "modern" children, their owners/parents, didn't spend the time or have the inclination to teach or discipline them. The exact same type of people who raise feral kids will also raise feral dogs. When a strong, intelligent, willful animal is allowed to mature with no training or discipline they are dangerous. Most people do not think of Chihuahuas as dangerous, but they would if they weight 70#. I have ran across more than one undisciplined one that was a snarling ankle nipper, who if embolden by more size would be truly dangerous. I have met others who were very sociable. Take a colt and train it ride and be a show animal, then take its sibling and turn it loose on the range and see what kind of terror he becomes. When the natives on the reservation near my brother go to round up some of the horses running wild, they start out by shooting the herd stallion because he will aggressively attack both man and beast with hooves and teeth and they don't read Disney books.
I firmly believe a Pit Bull can be raised as a trust worth pet, but the owner has to put in the time and effort. No time and effort and you could very end up with 60 or more pounds of undisciplined aggression. Raise a kid without putting in any time or effort and you may well end up with 150# or more of undisciplined aggression terrorizing the streets. In fact society is producing such an over abundance of such creatures that our prisons are full and few areas of the country are safe from them.
Yes, good parents and dog owners sometimes end up with bad kids and dogs, but they end up with far and away fewer than those who don't put in the time and effort.