Distinguishing between Degrees of Disability:
The ADAs initial definition of "disability" back in the early 1990's was rather broad, even though they didn't include some groups that should have been included. However, the ADA's early figures also included quite a few people with "minimal" impairment. They hadn't yet figured out that the degree of impairment ranges from minimal to severe in different individuals or sometimes in the SAME INDIVIDUAL from one day to the next.
People with "minimal" impairment are not particularly limited in their routine activities. They can usually pretty much go wherever they choose without having to worry about whether or not a particular facility or business is "barrier-free."
However, for that 20.8% of the population whose disabilities are "severe enough to significantly limit their activity" at any given moment in time, the accessibility factor becomes a major issue.
As disabled consumers, our awareness of the accessibility of a particular business or professional practice and their management's attitude towards the disabled community may well be deciding factors in whether or not we and our families will become or continue to be customers [clients/patients] of that business or professional practice.