Sure, different breeds excel at different things, but they are all still dogs, capable of doing the same things. Pit bulls, believe it or not, is one of the only breed types that excel at many of the things other do. Pit bulls are not naturally born aggressive fighters, but born more on the loyal, intelligent, and confident side. Specifically breed to be extremely human friendly, because these dog fighters never wanted a dog to turn on them, and anyone that did when they moved from bull baiting to dog fighting, were culled. That is the reason they are so sweet, and pit bulls make a sub-par guard dog, compared to shepherd, rottweilers, or dobermans, which were specifically breed to go after humans.
I also had retrievers, german shepherds, labs, and a sheepdog, pointers and now a pit bull. I too used to share your thoughts, but I was wrong, as I met many other pit bulls that never fit the stereotypical profile, and took the time to research, and even volunteer at shelters. Now I even train dogs on a part time basis, and pit bulls are nothing like you believe they are. If you do not have a dog at this time, but enjoy being with the, volunteer some of your time at a shelter walking dogs. You will have the opportunity to meet pit bulls, as shelters are riddled with them, although your dog of choice to walk may be a different breed. I can guaranteeing you that your perspective of these dogs will change, as they are not naturally aggressive, but rather extremely loyal and confident dogs, that are very versatile. Take those traits, give them to a person that fails to socialize their dog, abuses it, and trains it improperly, and you will possibly have an issue.
My pit bull out retrieves and retriever I have owned, and is also much more friendly towards other dogs, people, and even cats. She is also a champion of Frisbee and dock jumping. All that in a one year period of time, after sitting in a kill shelter for months, awaiting her time to be put down. She is the type of dog I can keep off leash and in the front yard with me, others can walk by with children and pets, and she doesn't even think about barking at them or going up to them, unless they are coming in my yard, which she wags her tail, and submissively walks up to them. It is what you make of them, and mine is friendlier than any other breed I owned. I am not telling you to get one, but please, get some real experience with the before you cast judgement.
Also, Dogsbite.org, that website you referenced earlier, is a website designed by a woman with a grudge, that thinks it may have been a pit bull that attacked her, but not positive, so she is on a mission to destroy all pit bulls. That website is highly discredited by ALL canine experts and ALL trusted canine groups. That website over inflates the truth, using bogus statistics, and percentages to make it seem like there is a major issue.