[Fannon]

Imho we also tend to underestimate the impact of cognitive biases on our own views and behaviors. We are often largely unaware of this. In this case, I find that Hanlon's razor is to simple with the black and white distinction of incompetence and malice. Biases often fall in neither category.

People who view themself as rational / technical might be even more prone to not realizing how much they are affected by this? If your self-image is that you are very rational person (more rational than others), you might be especially prone to denying and therefore not being aware of biases.