"Part of the reason is a form of professional racism that skips over Black people for promotions, even though they are qualified."

In my experience, as a white employee/consultant working for black managers and black owned companies, those two observations are connected.

When white employees slack off and adopt an "I dare you" attitude towards black managers/owners, they make it hard on everyone who works there. Its a form of blackmail and everyone can see what they're doing, but no one wants to push for his/her termination, because it might backfire on you, or the manager/owner/company.

On the other hand, employees at black owned companies get their fill of this garbage. The shared experience bonds people together.