Edit: btw, I think it's fine to "judge" people. My judgement, if that's what it is, can't really affect anyone's life, or actions and they're not even addressed to any particular individual.
You might even say they're actually my, you know- opinions.
I mean, there's no way to objectively decide what is acceptable risk. You can choose some arbitrary cutoff point, but it's always going to be an arbitrary cutoff point and nothing else.
And I think it's important to be able to look at facts (limited obviously by our ability to know them for sure) and make a decision about what you think is right to do based on them- and not just regarding risk. Regarding anything. In many issues that we have to deal with in our everyday life there is no cut-and-dried answer, so we just have to exercise our best, well, judgement.
You're right that we must leave such judgements open to re-evaluation, absolutely. That's what debating them on the internets is for :)