Actually it isn’t. If they worked for Blizzard then the American with Disabilites Act would require them to make accomodations for the person, and even then if the disability produces an “undue hardship” on the company to meet the needs of the disabled then it can be denied.
The only thing a video game is required to produce by American law is advanced communication services and even that is only required on games created after 1/1/2019. Any games before that could easily argue that their architecture doesn’t support it and it would be too difficult/costly to implement. A company is not legally responsible go make a game accessible to all disabilites.