As an example of "not understanding the problem space" it's mind-blowing sometimes to think about how a disability is only a disability in the context of a part

As an example of "not understanding the problem space" it's mind-blowing sometimes to think about how a disability is only a disability in the context of a particular way of living. If you're confined to a wheelchair and all the work surfaces and other affordances are above neck level for you, then it's a disability. But if those work surfaces are moved and extra space provided it's not a disability in that environment. It's just that people outside of a wheelchair can't identify the little assumptions and design features that accommodate them because they're the default in our culture.