Hardly - 26% [https://www.cdc.gov/ncbddd/disabilityandhealth/infographic-d...] of Americans have a recognized medical disability. Nearly that many are women of child bearing age, and can be discriminated against due to pregnancy status. 34% of Americans are over 50 years old (and officially protected as such).

You would be surprised how few people do not have a clear type of legal protection as part of some class - pretty much just fit, healthy, 18-40 something males really.