I would venture that all people are biased. It could not be otherwise, when you think about how any intelligent entity would have to work. We can only reason from our current set of beliefs, and these are often held quite emotionally, and defended against revision. It is just when the person talking or writing has different biases that one will view the other as biased. If the other’s viewpoint differs radically, we will see the that person as flat-out delusional. That may be the case, but perhaps that holds for us as well. We can see the other’s biases, but don’t do so well on seeing our own.
Michael Shermer, a psychologist and professional pseudo-skeptic, wrote a book describing why people believe strange things. However, he was the one who got to define which beliefs were strange. Guess who got a pass?