Even in real life, if you steal a car, I don't think you can get away by just returning it and promissing you'll be good.
You only have one life and one real you, so you shouldn't 'ban from society' for real crimes. However, in a game, you can have unlimited attempts at restarting with a fresh new chara after being totally banned. Giving amnesty to bots is like letting a criminal go on the promise that he will be good in the future.