I did not make that argument. I only argued that having free will or not makes no difference as long as we cannot tell whether we have it. Even supposing we all believed none of us has free will, it doesn't follow that we wouldn't agree to have rules. It also doesn't follow that believing we have or might have free will is what makes us behave well, but having rules does seem to help that.
As to fairness, there's also fairness to the rest of society -- if a person cannot help but commit crimes, then maybe they shouldn't be free to do so. You might think that unfair to the criminal, but it is certainly better for everyone else. Call this whatever you want, but it is pretty much how all societies work, from the most primitive to the most modern -- we have rules, and we seek to enforce them.
I'm not saying it's fair that we don't allow people to be free to act upon what is bad. I'm saying the system needs to be designed to be a rehabilitation modal and not a punishment modal because it's dehumanizing, amoral, and unethical to punish a person who is forced into the circumstances. The punishment modal doesn't help fix the problem and keeps a system from evolving to where people can be fixed like illnesses in the healthcare system.
Or look at it this way: if the universe is fully deterministic and we have no free will then what's the problem if a criminal goes to jail? It's not as if it means anything, and it was all pre-determined, no?
But the real answer is that we neither know for sure whether the future has been pre-determined, nor could we predict the future if it were, and we do not know if we have anything like free will, but we at least have the illusion of free will, so we have no choice but to act as if we do.
Rules can change, get better or worse and effect society in a little way. I have no problem with that! I’m not saying if someone cannot follow a rule it’s not good.
I’m saying the consequences of breaking a rule need to be a rehabilitation modal compared to a punishment modal. The illusion of free will is similar to humans once perceiving the world is flat. I’m a firm believer that it’s better to not live a life under an illusion and when the consequences to humanity are something like the justice system being built incorrectly in a dehumanizing manner. I find it heartless when a person feels like the people fated to suffer should just be damned instead of acknowledging a problem. Predetermination doesn’t make me into that type of person and while living several years with the illusion gone. I find that attempt something a person who hasn’t thought much about life (would say) while not thinking everything is determined.