Professionalism is prone to biases, self-delusion, too much trust in their narrow fields of expertise.
However, an aspirant to profession cannot take their knowledge from random sources. They need to learn from the same professionals. Indeed, would you learn maths from a medical doctor or news report? Would you learn surgical operation from a DIY YouTube video?
So it seems that professionals need to have honesty in their pursuit of truth, especially when judging outside of comfort zones of their areas. Yet, they are trapped in professionalism…