Roosters aren't like dogs. Even roosters that are raised by humans from the day they hatch can end up with bad attitudes, particularly the "game" breeds that are most often used for fighting. I've seen "pet" roosters go after cats, dogs, goats, children and even adult humans. Roosters that have been bred and trained specifically to attack other birds are not safe to have around. They'll attack hens, other poultry, and are often not afraid to go up against bigger animals or humans.
It's hard enough to rehome a tame, friendly rooster. I imagine it would be nearly impossible to find homes for ill-tempered, trained fighting cocks. And I wouldn't want to risk sending one of those birds to a home where it might attack the family dog or a little kid. They can do more than a little damage when they want to fight.
