To some extent it's just a name, and it's used across the industry. Similarly, "accessibility" doesn't scream "allow people with disabilities to use your product as well" - at some point, you just have to assume people either know what something means, or will figure it out as they go.

(In fact, "a11y" might even be better in that regard, in that it's clearly not a regular word, and thus might cause you to wonder what it means, whereas "accessibility" might lead you to make incorrect assumptions about what they're doing.)