I agree with you for the most part. But, it's not all of them who are willing to fight. There are many who are, absolutely, trained to do it, and still others used as bait dogs and "teaching" dogs because they *won't* fight. Furthermore, when they are abused, beaten, and starved into their aggression, THAT is conditioning them to fight. If they only way they get to eat that week is to fight to the death, then they'll do it.
If theres a dog that won't fight, there is no reason for dogmen to keep them. It is a useless dog to them and they will probably kill it quick and get on with their other dogs. Bait dogs are not necessary because they don't prove anything.
Think of fighting dogs more as... boxers, or mma fighters. Their men love them and will care for them greatly. They train them, get them in shape and strong, feed them good food. Theres money on the line. There is absolutely no point in wasting time with a dog that won't fight, nor will you have a strong dog that is starving and beaten. They get proven vs other pits that will fight. They have strong blood lines with winning dogs.
Dont get me wrong. There will be people that take this the wrong way and put random pit bulls they buy off the street because lol dog fights!! and do wrong things like use bait dogs or beat their dogs because they won't fight, ie vick. or random gangstas who want to have some fun in their basement. Its plain old dog abuse.
Its really important to be responsible if you own a pit because a lot of the world is gunna be against you. No dog parks, always on lease, good training manners. I had a DA pit (some sorta mix, ambull, amstaff maybe) that I always kept on lease and walked at odd times because people were idiots with their dogs off leash. We got into a fight once because someone ELSES dog ran at him. Its a pain to deal with and while I feel like I can manage a DA dog fine, its working around other people that make me hate it. Imagine if it was some 10lb puppy that ran at him!
I have a new dog now, a small pit and shes a wonderful beast. No DA at the moment (it can manifest at ANY time) and I hope it stays that way.