There are thousands of dog rescue groups, from the small to the large and the breed specific. There are more dogs waiting in shelters, foster homes, etc then there are homes for. Funds to operate these are stretched thin. Most of these dogs would make great pets for the right person. Even Cesar M told an elderly women who got two Terriers, plus had an older lab, that she should re home the terriers as that was too much high energy dog for her.
So why would you waste limited resources, limited shelter/foster home space/few homes for these animals you already have to go to, on dogs that have been pulled from a dog fighting raid? There's a reason pits are used for fighting instead of a collie or even a GSD. That's like taking the food bowl away from one dog and giving it to another.