Those arguing against it also can't not argue. But they will lose the argue (it is inevitable), and then society will continue to punish, because it can't not do so.
Determinism, whatever the logic of its premise, it intellectually bankrupt.
Believing these things is no more intellectually bankrupt than believing that the Moon has no choice but to revolve around the Earth.
What? You can still change your mind/update beliefs after being presented with new evidence, in fact if you're being rational, you actually have no choice but to do so. I suppose in some sense, the most 'free will' action is to choose to ignore evidence that would change your beliefs.
Rationality implies free will. I am a clockwork robot, and even if the cogs and gearsprings mechanically approximate rationality, it is really only the affectation of such. For irrationality would also just be obeying the same mechanical pathways encoded in my brain, thus neither is superior, or preferable. I can't even really have preferences, in a meaningful sense.
Also, the encoding of my personality is quite strong, and easily able to ignore the absurd snickerings of your arguments, so you won't win and change my mind, or enough minds of others to make it the dominant paradigm.
Punishment for wickedness remains. You lose.