Conversations about racism are deeply uncomfortable for most. No one wants to own being "racist". Perhaps that's why the term "unconscious bias" has garnered so much attention. It acknowledges that we can all be swayed by our own bias, even though we don't consciously mean to be.
The term reached a degree of prominence in response to the "Black Lives Matter" campaign in the US, as an explanation of police behaviour - sometimes deadly - towards people of colour.