> The idea that "life is meaningless" means that society cannot rely on you, because you'll do whatever strikes your fancy, whatever the consequences.
How does "life is meaningless" imply "life is useless"? Also, why would nihilism entail radical individualism? The core of nihilism is that since the indifferent universe is without meaning humans have to give it meaning, quite the opposite of what you're implying.
The fact that expected utility theory isn't nearly as scrutinized as the labor theory of value, whilst being at least as flawed, tells you something about the "value free" nature of modern econ.