There is an endless number of possible scenarios, with each having way too many situational details.
Are we talking a dog a person raised from puppyhood or an adult a person obtained? Was the puppy trained from the start correctly or spoiled/left to do as it wanted?
Are we talking biting owner, biting other people, biting dogs within the home or biting dogs outside the home?
The owner. Is the owner responsible with a modicum of sense? How much training experience and capability do they possess?
My generalized opinion: an unprovoked bite should never be tolerated. It is a "capital offense". Put the dog down.
The only bite scenarios I can imagine I would "reconsider" or tolerate from my dog would be
1) a "real", physical threat to me, from a person or an animal
2) a "real", physical threat to her from an animal or a person
Other generalizations:
1) A person who has raised a dog from puppyhood that bites has proven themselves to be an ineffective trainer and if they are unwilling to seek a professional trainer..put the dog down.
2) The average person has no business obtaining a dog with a "bite" history
3) There are way too many lovely, non-biting dogs that need rescuing rather than trying to be a saint and try to rehabiltate a dangerous dog.
4) An aggressive, biting dog should not be in public.
...that's my story and I'm sticking to it.
Wanna ask me my opinion of murderers and rapists? ;)
Edit: Greekman. Not considering the endless "scenario details
unprovoked, not mislead...euthanasia