If rationality does not help in the survival of our species, it is not rationality.

Being misinformed is not the same thing as being irrational. Misinformed rational beings do regrettable things. But the distinction between "misinformed" and "irrational" exists precisely because sometimes, rationality does not help in the survival of our species. But it is still rationality.

Nor should we conflate competence and evil. The most evil people in the world are so because of what they act to do, not how good they are at doing it. I put OBL and Hitler on the same moral footing as any other violent jihadist of racist. Rabble-rousing is a skill, not a character trait. Measuring people's moral worth by the damage we can attribute to them is not, in my view, rational.