Because the participants can't speak up against Biden like they do to Trump. Biden's supposed to be their savior, the representative of the Democrat party; if they go against him they have zero access to power in the WH left, and the "but it's a racist Republican" excuse won't work with the people they represent.
If they call out Biden's obvious missteps, they hurt their own cause. Biden already does a good job presenting himself as a racist, but even normies will see it if even these "civil rights" leaders call him out on it.
Biden's quote is divisive and racist on its face. All speech seeking to address issues based on skin color is.
The full context makes it even worse.
Great article that shows actual science proving WHO spreading pharma propaganda, and the best part is even normies can follow the argument