He was absolutely horrible. Chewed through everything. Demanded we sleep downstairs with him or he would yelp and wail all through the night. We'd take him outside, he'd use the bathroom. We'd leave and come back 5 minutes later, and he completely shat and pissed all over his kennel and walked all through it. So, it ended up that everytime we left, no matter the amount of time, when we came back, we had to clean up his kennel, give him a bath, and clean the floor around it. He was extremely rough with our kids and would bite at our youngest, who was only about a year and a half old at the time.
You are right, this has nothing to do with pitbulls. It has to do with shitty dog owners.
If you want to raise an aggressive dog, keep it caged up. Hell, try that with those kids of yours and see if they don't turn out aggressive as poo.
Just because you can convince a wild animal to live with you doesn't mean you should. If you don't have the time/space/patience/love to raise an animal the right way, then do not own one.
Also, anyone who buys a dog from a breeder, "reputable" or otherwise, should be forced to perform euthanasia for a day at the local animal shelter.