Some cities have or are contemplating ordinances which specify certain breeds as "dangerous" and won't allow citizens to keep them within "their" community on any terms.
Some folks love mean dogs, and feel comfortable in a gangland sort of way having them around. It's like having your home really be your castle, and really having your natural rights as a human being. Some people like to have firearms as their mode of self-defense, and consider that an inalienable human right. A serious dog can provide even more significant protection. My neighbors across the street have three Great Danes and a Dalmation with a large yard and a three-foot chainlink fence. It would be nothing for these dogs to just jump over it, and they bark at everyone who goes by.
We have never been robbed.
In a free country you can hate anything/anyone you want, and even say so. In a free country you can just shoot a dog that is menacing you, charging out at you with it's hackles up, or otherwise outside the owner's yard and infringing on your right to walk peaceably along your way. Or, if you have a dog, you can just send your dog out to greet the meany. Well, you'd need a real credible dog of your own.
I've lived in some tough places, and was known by the dogs I kept. The smartest dog ever was a German Shepard/coyote mix. The most loyal and "credible" was a Wolf/Malamute mix. When I got married I married her labs as well. I've got a ten-month old male lab who thinks he owns me, and he's the boss around here. He would stand off a cougar for me for all he's worth, but I'd rather have my "Wolfie" in a situation like that.
But don't get me wrong about the PitBull thing. I don't like them either. A few months ago while strolling in the 'hood, a pitbull with hackles raised charged out at me and my daughter. I used my most authoritative voice to warn him off, standing still and squarely facing him. Don't ever turn, run, or let fear show. I do my best to psych them out, but I'm prepared to defend myself/mykids. The problem with some of these breeds is that they are unpredictable and/or on "autoagression". It's not that they really are unpredictable, but actually predictable in the wrong ways. The ultimate problem is the owners are sometimes irresponsible as well.
All in all, I'd say it's not the dog's fault, but the owner's. In all justice then, the ordinances should require the arrest and deportation of the owner as much as the dog.
Likewise, when you are attacked by someone with a gun, it's sorta dumb to outlaw the gun. In this sense, it could be argued that when you are attacked by a Pittbull, a reasonable self-defense would include shooting the owner as well as the dog. But I despair of our cops/courts being that reasonable. It sends the wrong message to the owner to fail to communicate the consequences of his failure to keep his weopon in check.
However, if you can contrive to get a dog to bite you, run to the doctor, then to your lawyer. You will have the last laugh. Except in the slums/ghettos, that is. Nobody ever collects judgment decrees from bums.