Companies care about attracting all segments of society because if they can expand their applicant pool they will pay less for labor. If I am the only person smart enough to recruit qualified graduates from HBCUs then I get to be more selective in hiring and I also get to offer less wages but still fill the position.
Companies also want to be in the middle of the pack when it comes to sociocultural norms. There is safety in numbers. When everyone was adopting DEI initiatives, it was the safest for you to do it too. Now that everyone is abandoning DEI initiatives, it's also the safest to abandon it. There is no upside in being the fastest when it comes to bucking society's norms.