We all feel instinctively that we have free will, and if we haven't, then punishment of criminals is unjustified, as they were predestined from all eternity to be criminals.
I forget who it was (may have been either bluehillside or wigginhall: apologies for the lapse of memory) but only yesterday or the day before somebody remarked that we all instinctively feel that when we touch something - when we sit on a chair for example - we're actually touching it. But we're not: in fact we're only experiencing the repulsive force between our own electron shells and the electron shells of the object. With
everything.
All the time. Our instinctive feeling is knowably, demonstrably wrong, so it's not a reliable guide to the truth of the matter.
Nietzsche was far from the only philosopher to use the example of criminals in the discussion of free will v. determinism*: but to use this, as Alan Burns has on several occasions, as a strike against determinism is to commit the
ad consequentiam fallacy. A thing can be as unpleasant and unappealing as you (don't) like, but your abhorrence of the consequences won't change reality. If it is the case that there is no free will then there's no
ultimate justification for punishing criminals: but then, if there's no free will then we can't say that it's unjustified since if the criminal's acts were determined, then so are ours in exactly the same way. In real life however it leaves little or even nothing unchanged: if it could be demonstrated that there was no such thing as truly free will, punishing criminals may still be justified on pragmatic grounds, i.e. as a society-protecting mechanism. The proximate justification, in the absence of an ultimate one, will have to do.
* Spinoza, of whom Nietzsche was a great admirer, also denied free will.