A few years ago our company had a layoff. One of the employees let go was absolutely horrid at her job. Rude, obnoxious, would hang up on customers, even all her co-workers pretty much despised her.
Oh, and she was a "person of color".
She filed for wrongful termination and bragged about the $25K the company quickly gave her to not file suit.
"Cant fire because of..." means "Can't fire without paying out!"
Most cities and states have a ‘human relations commission’, or something similar.
It pretty much ensures that there is a ‘cost’ associated with laying off or firing a minority, if they choose to file a complaint.