I mean they don't HAVE to, unless there's some law I'm not aware of can't they just say "sorry not sorry colorblind people" or something. The MBAs will say HAVE to because maximizing shareholder value.
Accessibility lawsuits are common and frequent. Everyone gets them. It's sort of an open secret in the software world, not sure why it doesn't get discussed more. I guess the business people just consider it CODB, and developers prefer to believe it isn't real.