Lawdog, I'm not surprised at your reaction. The prong/pinch collar does look like a torture device (especially to the general public). And, like a torture device, it relies on pain to control the dog.
When the dog pulls, the "prongs" (note they are not pointed, however) poke into the dog's neck. Some people want to excuse it as being like a bite of a mother dog (what mother dog bites all the way around a neck like that? *L*). But the plain fact is that the pain of the collar keeps the dog from pulling. Many, if not most, of those using the prong collar use it instead of proper training. It's become the "tool of choice" for people with dogs they can't seem to control otherwise.
I have a couple of prong collars here and I have used them on occasion with a dog that pulls particularly bad or the rare dog that I feel NEEDS some painful consequence in order to stop a behavior. Used sparingly, they are a good tool and a relatively safe one as they don't tend to create injuries (like a choke chain might).
What I don't like about the prong is that it's vastly over-used. If someone has to always walk their dog on a prong, then there's been a lack of training somewhere along the line. In addition, training with the use of pain as your main "motivator" diminishes the quality of the relationship between you and your dog. There are better ways to train.
Melanie and the gang in Alaska