The definition of selective knowledge is like hexagon. Why is there so much objectivity?

Is there any specific, unproven ability that one can ignore the facts? In various studies, they may not care to be objective because that would require looking at various angles dispassionately which this person has no intention of doing. In formal setting, and when this arrogance is displayed in order to dismiss another perspective, it is termed as “impermissible viewpoint discrimination”

What is our best guess so far?