Not sure if you're correct, but I sure hope you're not. At the very least I've never worked anywhere that this would impact someone's assessment, in fact we have policies in place to make extra sure such bias isn't introduced.
Could you please expound on what your experience is?
What type of policies would prevent bias at the places you worked?
My company made a big deal about partnering with a contracting firm that specializes in placing people with disabilities. When asked at a townhall what the company was doing for people with the same disabilities who are employees, the company said they weren't doing anything. Another time I was talking to my manager about accommodations related to my disability and they told me that submitting for accommodations with HR probably hurt me because now the department head has documentation that I'm struggling in my role.
Could you please expound on what your experience is?