> When you make a bad decision, according to the other machines surrounding you (society) or your own brain's reward system, you are assigned blame or feel guilty because you should avoid making the same decision again in a similar situation.

But if free will does not exist then other machines (humans) aren't making these decisions either... it's turtles all the way down so to speak. You could go on to say that the entire system (of humans, society etc) is either determined or probabilistic, but still no free will exists. It is meaningless to say whether you should feel guilty or not etc. as it is just part of a system no one has any control over...

Edit:

What I meant to say is that moral responsibility exists like natural selection in evolution, it is there but we don't choose it to be there, it is part of the natural system we find our selves in.