Not because racism is somehow respectable, but I know the people howling the loudest are generally only concerned about their own group. You can go to the meetings, or get-togethers, of these identity-based civil rights folks and hear equivalent racism against other 'teams'. In general , they are superficial commentaries and not the institutional racism that existed in the U.S. historically. If an American wants to understand what real racism is, they should live in Asia or India for a while.
More and more it appears there has to be some grounding in the definitions of wage exploitation and the extraction of surplus value for any left movement to flourish. Otherwise the left is basically reduced to the equal opportunity, 'let me have it too' schtick of liberals. The former which of course can be remedied with charity.