I have a hard time believing you would feel that way if your son or brother, wife or girlfriend, mother or father, were murdered, raped, killed by a drunk driver, or killed by some street-racers.
I don't know what it's like for you in Sussex(and I know there is a lot of fear-mongering in the UK about knives and stuff), but I'm currently working with at-risk youth in Abbotsford, British Columbia. Abbotsford is the crime capital of Canada, beating out Toronto our biggest city.
I can tell you that there is definitely a level of crime and that there will always be a level of crime regardless of how lax, or how tight the laws in a country are.
To do what you are suggesting just seems irresponsible to me.
When some drug-lord down the street is getting teens to beat up other teens, because they suddenly decide they want more money, I have a hard time processing the idea of them deserving a chance to not go to jail.
To give criminals a "fair shot at it" then that would have to be the case with all criminals, regardless of crime, otherwise that would be discrimination. Therefore the pyro who keeps burning down buildings with people in them should be allowed to get "a fair shot at it" and get away to burn down another building with people in it. The rapist can rape again. The murderer can murder again.
Your thinking works great for farming sheep, but not for a country, not with law-abiding people involved.
Maybe you live in a place with not much crime, but criminals around here do not need "a fair shot at it".