I think there is a distinction. In this case literally the entire argument is “It has a small probability of success, but we should pursue it, because the probability if we don’t try is zero”. It would be valid to justify a low probability with a high utility, but sometimes people just ignore or refuse to calculate probabilities because they believe that all alternatives are futile, even in the face of repeated counterevidence pushing the probability ever-lower. While such a situation is possible, beliefs of this type are far more likely to be caused by rationalization.
I think there is a distinction. In this case literally the entire argument is “It has a small probability of success, but we should pursue it, because the probability if we don’t try is zero”. It would be valid to justify a low probability with a high utility, but sometimes people just ignore or refuse to calculate probabilities because they believe that all alternatives are futile, even in the face of repeated counterevidence pushing the probability ever-lower. While such a situation is possible, beliefs of this type are far more likely to be caused by rationalization.