[crimsonalucard]

Your argument applies to science fiction and other works that make grand speculations about the future. The future is not knowable thus it is useless and misleading to speculate according to your argument. Your counter argument is far more shallow and misleading.

Our progress towards the future happens regardless of a limit. So why write science fiction? Why write fiction at all? Because we're human. I speculate, therefore I am.

Either way your argument doesn't address the heart of the matter. Is my speculation correct? Or is it incorrect? You have failed to logically address this argument. On the other hand I have only said that one outcome is far more likely than the other, I have not been definitive about it either.