I’ve worked in and around affordable and market rate housing for my entire career.
Most of the focus with affordable housing has been income based. Some projects have focused on seniors and disabled (mobility mostly). I have come in contact with some projects that had a focus on persons living with AIDS, but not many. Veterans and homeless projects also.
Thinking about it, whether it’s income or ability…. the root is needing housing for folks with an extraordinary need not being met by the “market”.