Who thought this was a good idea? Probably people who had to type “accessibility” out a dozen times a day. Also marketing minded people who know a memorable title keeps people thinking about the topic longer.

Side note, numeronyms have been around for a long time. This isn’t something we just invented for a11y.

Also side note: I personally love “a11y” because it makes me think of “ally”, which is what we would all be to people with special needs if we religiously adopted a11y.