DAL, you're absolutely right about the breeding angle, but the same can be said for about 10 other breeds, and nobody is calling for their extermination. Breeding goes beyond the physical traits of aggressiveness, tenacity, and powerful jaws. Part of the bad news one hears from pit bull attacks, besides the often (but not always) moral deficiency of their owners, is that there was little attention paid to their lineage (other than for their aggressiveness) in breeding them.
I'm 55 years old, and I can recall over the years going back to my childhood that several other breeds have been under the same kind of scrutiny at various times and for the same kinds of reasons as pit bulls are today. When I was a child, it was german sheperds. When I was in my teens, it was doberman pinschers. In my twenties and thirties, it was rotweilers. For a while in the 1980s, it was saint bernards. Later, it was pit bulls. In each case, the focus of public attention on the issue eventually resulted in the social redemption of the breed - partly through better controlled breeding programs, and partly through social pressures on the people who misused the dogs.
I completely understand why people feel the way they feel about pit bulls, but I do think that it is an over-reaction. I worked for 6 years in a level 1 trauma center back in the 1980s in a southern California city with a significant ghetto and all the problems that are associated with that. In those six years, I saw thousands of gunshot victims, stabbing victims, abuse victims, suicides, accident victims, and pretty much every kind of traumatic injury you can conceive of. In all those cases, I can recall only one dog mauling case, and the dog in question was a saint bernard. And yet, we had gangs, gang related crimes, and gangbangers who owned pit bulls.
I'm not saying the problem doesn't exist, but I AM saying that it is not nearly as common as people think, and that the scope of the problem is inflated by a media based on an "if it bleeds, it leads" ethic. It would be a real shame to exterminate an otherwise interesting breed of dog because of media pressure and public hysteria. All I am advocating is for is a more reasoned response, less fueled by anger, from people who don't like pit bulls. Because tomorrow, the focus of public anger could be the breed that you do like.