Huh? That is not at all what I read from Scott Aaronson on this and I don't see how your interpretation can be supported upon a close reading.

My interpretation about this is that people who are smugly contrarion suffer from their own rationality bias that leads them to a higher likelihood of truth but at the cost of a much, much higher variance.

Sure, the smug contrarians taught to wash our hands between surgery & discovered America, but they were also the ones who ushered in the French Revolution, the Cambodian Genocide & the Zimbabwe Land Reforms.