"For this reason, I would also label as "morality" the belief that truthseeking is pragmatically important to society..."
This seems like a naive understanding of what morality is. It seems like you are referring to a certain subset of ethics, in this case utilitarianism (do what promotes the greatest good among the greatest number). But this is just one part of a class of normative ethical theories. The class to which I'm referring to is consequentialism where essentially, the end justifies the means. I'd rather not get off topic here and simply state that a morality-driven pursuit of truth does not necessarily mean that the person is motivated by the "greater good".
Also, Spock's calculation is off by one order of magnitude, not two. He predicts, roughly, a 98% chance of destruction yet you say in practice, the Enterprise is destroyed 10% of the time. That's just about one order of magnitude off.